The challenge comes down to a distinction that sounds minor but matters enormously. In the syn form of a β-amino alcohol, the amino and hydroxyl groups sit on the same side of the carbon chain; in the anti form, they point to opposite sides. Both forms are chemically valid, but enzymes and drug targets can distinguish between them with ruthless precision, so a synthesis that delivers an uncontrolled mixture of the two is of limited use. The workhorse transformation for building these frameworks is the Henry reaction, a well-studied carbon–carbon bond-forming process that couples an aldehyde with a nitroalkane to produce a β-nitro alcohol. Because the nitro group can later be reduced to an amino group using well-established chemistry, the Henry reaction is a natural gateway to β-amino alcohols. The problem is that most catalytic versions of the reaction favor the syn product, leaving the anti form frustratingly out of reach.

That long-standing gap is now the target of a new study from Chiba University in Japan. A research team led by Professor Takayoshi Arai of the Graduate School of Science, working with co-authors Dr. Soushi Tsurusaki and Dr. Hidesato Iwama, has designed a chiral nickel catalyst that steers the Henry reaction decisively toward the anti product. The study, published online in the journal Angewandte Chemie International Edition on September 24, 2026, describes a catalyst architecture that does something conceptually elegant: it recruits several different types of molecular interactions at once, marshaling them in a single coordinated system to control how two reacting molecules find each other.

The catalyst, designated o-X-F4-PyBidine-Ni(OTf)2, where X is either bromine or iodine, is built around a nickel complex containing a molecular scaffold called PyBidine. The key innovation lies in a deliberate chemical modification: the researchers installed a bromine or iodine atom at a specific position on the ligand, creating a site capable of forming a halogen bond. Halogen bonding is a non-covalent interaction that arises when a region of positive electrostatic potential, known as a σ-hole, forms on the outer surface of a halogen atom. That positively charged patch can attract electron-rich functional groups on a nearby molecule, effectively gripping the aldehyde substrate and locking it into a defined orientation before the reaction takes place.

But halogen bonding is only one player in what is essentially a molecular choreography. Alongside the halogen bond, conventional hydrogen bonding, the familiar attractive force between a hydrogen atom and an electronegative atom, helps hold the aldehyde in place and simultaneously activates it toward reaction. Meanwhile, the nickel center, working in concert with a base called triethylamine, activates the nitroalkane, priming it to form the new carbon–carbon bond. The result of this multi-pronged arrangement is that the two reacting partners are held in a stretched-out, precisely aligned geometry that channels the reaction toward the anti product rather than the syn product that conventional catalysts tend to deliver.

The performance numbers are striking. Using alcohol as the solvent, the catalyst achieved up to 96:4 selectivity for the anti form over the syn form across many combinations of reactants, meaning that for every hundred product molecules, as many as ninety-six carried the desired anti geometry. Equally impressive is the enantioselectivity: the reaction delivered up to 99 percent enantiomeric excess, which means nearly every product molecule was the same one of the two possible mirror-image versions of the anti form. For a field where controlling both relative and absolute stereochemistry simultaneously is the central difficulty, those figures represent the kind of result that can change how chemists approach an entire class of targets.

The substrate scope adds to the practical appeal. The method proved compatible with a wide range of aromatic aldehydes, including examples bearing heterocyclic rings, which are common features in pharmaceutical compounds and often complicate catalytic reactions. Several kinds of nitroalkanes also worked as coupling partners. That breadth matters because a synthetic method that only functions with a narrow set of substrates rarely escapes the laboratory; one that tolerates diverse aromatic and heteroaromatic aldehydes has a realistic path toward applications in medicinal chemistry, where β-amino alcohol motifs recur constantly. As Professor Arai put it, the coordinated functioning of diverse interactions on a single catalyst represents an advance in state-of-the-art catalytic chemistry.

Curious about why the system works so well, the team turned to computer simulations to dissect the mechanism at a finer level of detail. These calculations revealed that the most favorable reaction pathway involves a halogen bond between the catalyst’s bromine atom and the aromatic ring of the aldehyde, working in tandem with hydrogen bonding and interactions between the nickel center and the nitro group of the nitroalkane. In other words, the selectivity is not the product of any single interaction but of several weak forces acting simultaneously, each contributing to the precise positioning of the reacting molecules. Interestingly, the bromine version of the catalyst was often more active than the iodine variant, possibly because bromine’s smaller size leaves more room for the substrate molecules to approach the reactive site.

Beyond the immediate synthetic payoff, the study carries a broader conceptual message for chemists who design catalysts. Halogen bonding, though increasingly recognized in recent years, has rarely been deployed alongside hydrogen bonding and metal coordination within a single catalytic system, particularly in protic solvents like alcohols, where such delicate interactions are easily disrupted. Demonstrating that these forces can cooperate on a metal catalyst under practical conditions opens a design space that catalyst developers have barely explored. Professor Arai noted that the higher-ordered cooperation of halogen bonds and hydrogen bonds on a metal catalyst in protic solvents is fascinating for the development of artificial metalloenzymes and halogen-bond-driven medicines, pointing toward catalytic systems that mimic the sophisticated multi-interaction control that enzymes achieve naturally.

The longer-term implications extend in several directions at once. For synthetic chemists, the work provides a dependable route to anti-β-amino alcohols, since the nitro group in the products can be readily converted into an amino group by well-established reduction chemistry, completing the gateway from the Henry reaction to the desired building blocks. For catalyst designers, it offers a template for engineering selectivity not through brute-force steric bulk but through the cooperative action of multiple weak, directional interactions. And for the emerging field of artificial metalloenzymes, synthetic catalysts that aspire to enzyme-like precision, it demonstrates that nature’s strategy of combining many subtle molecular forces can be reproduced in a small, human-made framework. The research was supported by the IAAR Research Support Program at Chiba University and by JSPS KAKENHI grant number 26K01496, and the authors declare no conflicts of interest. What began as an attempt to solve a stubborn stereochemical problem may end up reshaping how chemists think about controlling reactions altogether, one weak interaction at a time.

Subject of Research: Halogen-bond-assisted anti-selective Henry reaction using a chiral nickel catalyst for β-amino alcohol synthesis

Article Title: Innovative nickel catalyst unlocks hard-to-make β-amino alcohols

Article References: Innovative nickel catalyst unlocks hard-to-make β-amino alcohols. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: nickel catalyst, β-amino alcohols, Henry reaction, halogen bonding, hydrogen bonding, enantioselective synthesis, organocatalysis, stereochemistry, Angewandte Chemie, Chiba University, artificial metalloenzymes, pharmaceutical building blocks

The elegance of the approach lies in what the researchers did not do. There is no multi-step synthesis, no high-temperature calcination, no hydrothermal autoclave, and no template removal. Instead, the team applied a direct current to a copper electrode immersed in a plating bath containing nickel salts, and they tuned the chemistry of that bath with two familiar ions: nitrate and chloride. Each ion plays a distinct role. Nitrate is known in electroplating circles for its ability to modify deposit morphology and even darken nickel films by altering how the metal nucleates and grows on the surface. Chloride, meanwhile, influences particle size and film compactness. By adjusting the balance between the two, the researchers could jointly control two things that usually fight each other in catalyst design: the ratio of metallic nickel to nickel hydroxide in the final film, and the mesoporous architecture that determines how much of the catalyst surface is actually reachable by electrolyte.

Why does that dual control matter so much? The answer lies in the complementary weaknesses of the two phases. Metallic nickel is an excellent electrical conductor, but on its own it is a mediocre oxygen evolution catalyst; the reaction intermediates bind to its surface with the wrong energetics, and the kinetics stall. Nickel hydroxide, by contrast, offers far more favorable adsorption sites for the oxygen-containing intermediates that form during water oxidation, but it is a poor conductor and, in many preparations, suffers from structural reconstruction during operation, gradually converting into other phases whose activity can drift over time. The hybrid electrode sidesteps both problems. Metallic nickel domains act as an internal electron highway, shuttling charge to and from the catalytically active hydroxide regions, while the low-crystallinity nickel hydroxide provides the reactive interface where water molecules are oxidized. The result is a composite in which each phase covers for the other’s deficiencies.

The performance numbers back up this design logic. At the benchmark current density of 10 milliamperes per square centimeter, the Ni/Ni(OH)2 electrode required an overpotential of just 254 millivolts, meaning the researchers had to apply only that much extra voltage beyond the thermodynamic minimum to get water oxidation underway at a useful rate. Equally telling is the Tafel slope, a measure of how quickly current rises as additional voltage is applied. The hybrid electrode delivered a Tafel slope of 50.3 millivolts per decade, indicating markedly accelerated reaction kinetics compared with conventional nickel-based catalysts. In practical terms, a lower Tafel slope means the catalyst does not need ever-larger voltage penalties as the electrolyzer is pushed toward industrial current densities, which is precisely where energy efficiency is won or lost.

Durability, the quiet killer of promising electrocatalysts, was also addressed head-on. Many laboratory catalysts post impressive initial numbers only to degrade within hours as their active layers dissolve, delaminate, or restructure. The Jingdezhen team subjected their electrode to a 100-hour chronopotentiometry test at a demanding 50 milliamperes per square centimeter, a current density far closer to real electrolyzer operation than the standard 10-milliamp benchmark. The electrode held its performance throughout, a result the researchers attribute to the in-situ nature of the fabrication: because the hybrid film is grown directly on the copper substrate rather than deposited as a powder and glued on with a polymer binder, the catalyst-substrate interface is intimate and mechanically robust, resisting the bubble evolution and mechanical stress that peel weaker electrodes apart.

Mechanistic analysis of the composite revealed why the interface between metallic nickel and low-crystallinity nickel hydroxide is so productive. The two phases form a coupled system in which electrons generated during the oxidation of hydroxide species can transfer efficiently across the phase boundary into the metallic network, avoiding the charge accumulation that throttles pure hydroxide electrodes. The low crystallinity of the hydroxide component is itself an asset rather than a defect: disordered structures typically expose a higher density of under-coordinated metal sites, edges, and defects that serve as active centers for the four-electron water oxidation sequence. Meanwhile, the anion-regulated deposition produced a mesoporous morphology with finely dispersed particles, maximizing the electrochemically accessible surface area and ensuring that bubbles generated during operation can escape easily rather than blanketing the surface.

The choice of copper as the substrate deserves its own note. Copper is cheap, conductive, and mechanically robust, and it is increasingly favored in the electrocatalysis literature as a support that can even participate chemically in the catalysis, promoting the transformation of nickel hydroxide into higher-valent nickel species that are considered the true active phase for oxygen evolution. By growing the catalyst directly on copper foil or mesh in a single electrochemical step, the researchers eliminated the need for expensive conductive additives, binders, and the energy-intensive processing steps that inflate the cost of conventional electrode manufacturing. For an industry trying to drive down the capital cost of alkaline water electrolyzers, a fabrication route that is essentially room-temperature electroplating is a genuinely attractive proposition.

The broader context makes the result more than a laboratory curiosity. Alkaline water electrolysis is the most mature hydrogen production technology, but its efficiency is capped by the large overpotential of the oxygen evolution reaction at the anode, which can waste hundreds of millivolts of electrical energy per cell. Every millivolt saved translates directly into kilowatt-hours saved per kilogram of hydrogen produced. Nickel-based catalysts have long been the workhorse candidates for replacing precious metals in this role, and recent years have seen an explosion of strategies, from nickel-iron layered double hydroxides to doped nitrides and oxyhydroxides, aimed at squeezing more activity out of earth-abundant elements. What distinguishes the new work is its emphasis on process simplicity: rather than adding complexity, it uses the intrinsic chemistry of two common anions to achieve phase control, morphology control, and interface engineering in a single deposition bath.

The anion-regulation concept also opens a tunable design space that other groups can explore. Because nitrate and chloride each exert distinct effects on nucleation density, particle size, and phase composition, varying their relative concentrations offers a continuous dial for optimizing the catalyst, rather than a discrete choice between recipes. The same principle could plausibly extend to other transition metal systems, including nickel-iron and nickel-cobalt chemistries, where anion-directed electrodeposition might similarly couple conductive metallic phases with active hydroxide phases. The researchers suggest that their work offers a facile route to low-cost, high-performance non-noble-metal OER electrodes with direct implications for industrial alkaline water electrolysis, and the combination of a 254-millivolt overpotential, a 50.3-millivolt-per-decade Tafel slope, and 100 hours of stable operation at 50 milliamperes per square centimeter gives that claim real weight.

Challenges remain before such electrodes see service inside a commercial electrolyzer stack. Long-term testing at even higher current densities, in flowing industrial electrolyte, and under the intermittent loads characteristic of renewable-powered hydrogen plants will be needed to confirm that the hybrid structure survives years rather than days. Scaling from small copper substrates to meter-scale electrode plates will test whether the anion-regulated deposition remains uniform across large areas. Still, the study is a reminder that some of the most consequential advances in clean energy chemistry come not from exotic new materials but from smarter control of the ones we already have. Two cheap ions, one electric current, and a copper plate may turn out to be an unlikely recipe for making green hydrogen a little more affordable.

Subject of Research: Anion-regulated one-step electrodeposition of Ni/Ni(OH)2 hybrid electrocatalysts for the alkaline oxygen evolution reaction

Article Title: NO₃⁻/Cl⁻-regulated one-step electrodeposition for in-situ fabrication of Ni/Ni(OH)₂ hybrid structures toward high-efficiency alkaline oxygen evolution reaction

Article References: Shi, J., Fan, J., Xv, J., Sun, L., Gong, Q., Huang, Y., Zhang, K., & Zhang, H. (2026). NO₃⁻/Cl⁻-regulated one-step electrodeposition for in-situ fabrication of Ni/Ni(OH)₂ hybrid structures toward high-efficiency alkaline oxygen evolution reaction. Ionics. https://doi.org/10.1007/s11581-026-07490-3

Image Credits: AI Generated

DOI: 10.1007/s11581-026-07490-3

Keywords: oxygen evolution reaction, water electrolysis, green hydrogen, electrodeposition, nickel catalyst, nickel hydroxide, nitrate regulation, chloride regulation, copper substrate, Tafel slope, electrocatalyst durability, alkaline media

The core of the discovery is a structural detail measured at the scale of a single bond. By engineering molybdenum and nickel atoms into asymmetric pairs separated by just 2.85 angstroms, the researchers created an active site geometry that changes the fundamental pathway of the oxygen evolution reaction. In the traditional adsorbate evolution mechanism, oxygen–oxygen bonds form through a sequence of adsorbed intermediates whose energetics are locked together by so-called scaling relations, meaning that improving one step inevitably worsens another. The shortened Mo–Ni distance instead enables an oxide path mechanism with direct O–O coupling, in which the oxygen–oxygen bond forms without passing through the full ladder of adsorbed intermediates. Because this route bypasses the scaling relations entirely, the catalyst escapes the theoretical ceiling that has constrained activity and stability trade-offs for decades.

Density functional theory simulations, performed by a team at Wuhan University led by Xiang-Kui Gu, provided the mechanistic blueprint before the material was fully characterized. The calculations showed that the asymmetric pairing of a high-valence molybdenum atom with a nickel neighbour redistributes electronic density across the active site, lowering the energy barrier for direct O–O coupling while keeping the nickel centre from over-oxidizing and dissolving. This dual role matters because catalyst degradation at high current densities usually stems from exactly that failure mode: nickel oxyhydroxide phases can restructure, dissolve, or passivate when pushed to the potentials required for industrial operation. The molybdenum partner acts as an electronic stabilizer, absorbing and buffering charge so the nickel site can cycle through oxidation states without collapsing structurally.

Experimental characterization confirmed the predicted geometry. X-ray absorption spectroscopy, electron microscopy, and complementary structural probes verified that the molybdenum atoms sit in the intended coordination environment adjacent to nickel, with the 2.85 angstrom interatomic distance intact after synthesis. The catalyst was fabricated as an electrode material rather than a powder that would need binding to a substrate, an engineering choice that matters for real electrolysers where catalyst layers must withstand gas evolution, bubble formation, and mechanical stress at current densities far beyond what laboratory half-cell tests typically explore. The fabrication and characterization work was carried out at Shanghai Jiao Tong University under the supervision of Yancai Yao and Lizhi Zhang, with Xingyue Zou and Jinzhe Zhang contributing equally as lead authors.

The performance numbers are what set this catalyst apart from the crowded field of oxygen evolution materials. In laboratory-scale testing, the anode delivered exceptional durability for over 2,000 hours at 3 amperes per square centimetre, a current density that corresponds to the operating regime of commercial alkaline and anion-exchange membrane electrolysers rather than the gentle conditions of academic benchmarking. Most reported catalysts are evaluated at 10 milliamperes per square centimetre, three hundred times lower, where degradation mechanisms barely have time to manifest. Sustaining stable oxygen evolution at industrial current density for nearly three months of continuous operation is a stress test that very few non-precious-metal catalysts have passed, and it directly addresses the gap between laboratory records and electrolyser requirements.

The researchers then integrated the catalyst into a laboratory-scale anion-exchange membrane water electrolyser, a device architecture that combines some of the advantages of proton-exchange membrane systems with the cheaper, non-precious-metal chemistry possible in alkaline conditions. The anode produced low cell voltages of 1.78 to 1.95 volts at current densities of 2 to 3 amperes per square centimetre, alongside more than 1,200 hours of stable operation at the upper end of that range. Cell voltage is the single most important determinant of electrolyser energy efficiency, because every additional tenth of a volt translates directly into extra kilowatt-hours per kilogram of hydrogen. Voltages in this range at such high current densities represent a competitive operating point against commercial benchmarks that typically rely on more expensive electrode materials.

To prove commercial viability, the team scaled the technology into a 71 square centimetre per cell anion-exchange membrane electrolyser stack, developed with industrial partners including Headway Technology Group in Qingdao. The stack produced hydrogen with purity exceeding 99 percent while cutting energy consumption and hydrogen production costs by 10 to 17 percent compared with commercial benchmarks. Those percentages may sound incremental, but in the economics of hydrogen production, where electricity is the dominant cost and margins are thin, a double-digit reduction in energy demand per kilogram of output is the difference between green hydrogen being subsidized and being competitive. The researchers also conducted a technoeconomic analysis alongside the electrochemical testing to quantify the cost implications, and the results suggested the catalyst’s nickel-and-molybdenum composition avoids the price volatility of iridium and ruthenium that burdens acidic electrolyser anodes.

Perhaps the most consequential step is the one most often skipped in catalyst papers: manufacturing. The team established a mass-production line for the oxygen evolution reaction electrodes, demonstrating that the synthesis route can be executed at industrial scale rather than only on small laboratory substrates. Scalability has quietly become the graveyard of electrocatalysis research, with countless high-performing materials depending on synthesis conditions, precursor costs, or deposition techniques that cannot be translated to square-metre electrode areas. By proving scalable manufacturing viability in parallel with performance, the researchers addressed the full chain from atomistic design to deployable hardware, which is what distinguishes an engineering advance from a laboratory curiosity.

The scientific significance extends beyond this single material. The oxide path mechanism with direct O–O coupling, enabled by a precisely tuned interatomic distance, offers a design principle that other researchers can pursue: instead of searching for adsorbate intermediates with perfect energetics, engineer the active site geometry so the rate-limiting bond forms directly between two oxygen species. Related strategies have shown promise in acidic water oxidation on ruthenium-based systems, but demonstrating the principle on an abundant, inexpensive nickel–molybdenum platform in alkaline conditions, at industrial current densities, and in a working electrolyser stack substantially broadens its practical reach. It suggests that the scaling relations, long treated as an iron law of oxygen evolution catalysis, can be sidestepped through structural design rather than elemental substitution.

Challenges remain before this catalyst reshapes the hydrogen economy. The reported demonstrations, while impressive, involve a 71 square centimetre cell in a stack, whereas commercial electrolysers operate with much larger electrode areas and thousands of hours of field exposure across variable renewable power inputs. Long-term behaviour under fluctuating loads, impurity tolerance in real water feeds, and the economics of integrating the electrodes into complete electrolyser systems at gigawatt scale all require further validation. Still, the combination of 2,000-hour stability at 3 amperes per square centimetre, low cell voltages in a membrane electrolyser, double-digit cost reductions in a commercial-scale stack, and an operating production line represents one of the most complete demonstrations of an oxygen evolution catalyst to date. As governments and industry commit hundreds of billions of dollars to hydrogen infrastructure, advances that attack the anodic bottleneck with cheap, durable, scalable materials are exactly the kind of unglamorous chemistry on which the zero-emission fuel future will ultimately depend.

Subject of Research: Asymmetric Mo–Ni atom pair electrocatalysts for durable oxygen evolution in industrial alkaline water electrolysis

Article Title: Asymmetric Mo–Ni atom pairs enable scalable water oxidation at industrial current densities

Article References: Zou, X., Zhang, J., Xie, J., Dong, H., Zhou, B., Dai, J., Zhao, L., Wang, J., Zhan, G., Lian, W., Cao, X., Liu, B., Gu, X.-K., Yao, Y., & Zhang, L. (2026). Asymmetric Mo–Ni atom pairs enable scalable water oxidation at industrial current densities. Nature Sustainability. https://doi.org/10.1038/s41893-026-01942-4

Image Credits: AI Generated

DOI: 10.1038/s41893-026-01942-4

Keywords: green hydrogen, water electrolysis, oxygen evolution reaction, electrocatalysis, nickel catalyst, molybdenum, anion-exchange membrane, oxide path mechanism, industrial current density, catalyst durability, Nature Sustainability, energy transition