In a groundbreaking advancement in the field of catalysis and chemical engineering, researchers have unveiled a novel method for propane dehydrogenation (PDH) that operates effectively under near-ambient conditions, challenging decades-old assumptions about this highly endothermic reaction. Traditionally, PDH—used to convert propane into propylene, a vital feedstock for polymer manufacturing—demands extreme reaction temperatures often exceeding 600°C. Such harsh conditions not only consume vast amounts of energy but also contribute to catalyst degradation through sintering and carbonaceous coke deposition. Addressing these critical challenges, a collaborative research team led by Professors ZHANG Tao and WANG Aiqin at the Dalian Institute of Chemical Physics (DICP), Chinese Academy of Sciences, alongside Professor GAO Yi’s team at the Shanghai Advanced Research Institute, has introduced a revolutionary copper single-atom catalyst (SAC) system that utilizes water vapor and light to achieve PDH under significantly milder conditions.
The research, recently published in Nature Chemistry, details an innovative reaction pathway where the Cu₁/TiO₂ single-atom catalyst, when exposed to water vapor and illuminated by light, facilitates propane dehydrogenation at temperatures as low as 50 to 80 degrees Celsius. This marks an unprecedented breakthrough, indicating that the PDH process can be driven efficiently by photo-thermo catalytic techniques rather than relying solely on traditional thermal energy inputs. The incorporation of water vapor into the reaction environment not only reduces the thermal barrier but also catalytically participates in the reaction mechanism without being consumed, presenting a paradigm shift in how endothermic dehydrogenation reactions might be understood and engineered.
At the heart of this transformation is the unique role played by the copper single atoms dispersed on the titanium dioxide support. These individual copper atoms act as highly active catalytic centers that synergize with water molecules and light energy. Under illumination, the Cu₁/TiO₂ catalyst undergoes photocatalytic water splitting, generating reactive hydrogen and hydroxyl species on the catalyst surface. Hydroxyl radicals then engage directly with propane molecules, abstracting hydrogen atoms and resulting in the formation of propylene and water. This reaction mechanism starkly contrasts with conventional PDH and oxidative dehydrogenation pathways, which typically depend on high thermal activation and often create unwanted byproducts or suffer from catalyst deactivation.
In continuous-flow fixed-bed reactor experiments, the team achieved remarkable reaction rates, reaching up to 1201 micromoles per gram of catalyst per hour, a metric that underscores both the efficiency and potential scalability of this method. Operating near room temperature and under water vapor, the novel photo-thermo catalytic system minimizes energy consumption, offering a sustainable alternative to the existing high-temperature PDH processes that dominate the petrochemical industry. This innovation addresses long-standing industrial challenges and opens new avenues for more energy-efficient production of propylene, a cornerstone molecule for plastics, fibers, and rubbers worldwide.
Beyond propane, this method’s versatility extends to other light alkanes such as ethane and butane, underscoring the broad applicability of the copper single-atom catalytic system combined with water and light. The researchers demonstrated that the catalyst system could directly harness sunlight as an energy source, favoring the integration of renewable energy into hydrocarbon conversion processes. Such developments align closely with global efforts to reduce carbon footprints and transition towards cleaner, solar-driven chemical manufacturing.
Photocatalysis traditionally involves light-induced electron-hole pair generation to drive chemical reactions, but this study presents a nuanced hybrid of photo-thermo catalysis that leverages both photon energy and moderated thermal inputs to break the tight C–H bonds in propane molecules. The generation of hydroxyl radicals plays a pivotal role in this catalytic mechanism, acting as highly reactive intermediates that selectively strip hydrogen atoms from propane, thus facilitating the formation of propylene with minimal side reactions. Importantly, water’s role as a catalytic medium rather than a reactant underpins a sustainable approach that avoids excessive reagent consumption and waste formation.
This discovery not only offers a path to more efficient and environmentally benign propylene production but also lays foundational knowledge for designing next-generation heterogeneous catalysts that can operate under ambient conditions. The insights gained into the single-atom copper catalytic sites pave the way for rational design of atomically dispersed catalysts tailored for specific photochemical and thermochemical processes in the energy and chemical industries. In essence, controlling catalytic activity at the atomic scale, aided by light and water, promises to revolutionize how complex molecular transformations are achieved in the future.
Moreover, the implication of utilizing solar energy directly to drive PDH aligns with the growing imperative to decarbonize the chemical industry, often cited as a major contributor to global carbon emissions. The ability to carry out industrial-scale chemical synthesis powered by sunlight and water vapor could dramatically reduce reliance on fossil fuel combustion, thus steering chemical manufacturing toward more sustainable paradigms. Such technologies have vast potential applications, ranging from portable chemical reactors to decentralized production units harnessing natural sunlight.
Professor LIU Xiaoyan, a corresponding author of the study, emphasized that this research not only introduces a breakthrough catalytic process but also establishes an important conceptual framework for high-temperature reactions driven principally by solar energy. This work signifies a vital stride toward marrying catalysis with renewable energy inputs, demonstrating how fundamental scientific insights can catalyze disruptive technologies in petrochemical processing. The combined expertise of the Dalian and Shanghai research teams exemplifies the vibrancy of multidisciplinary collaboration required to tackle energy-intensive industrial challenges.
The detailed mechanistic understanding revealed in this study also has profound implications for the future design of catalysts that leverage single-atom active sites, a field garnering immense attention due to the exceptional selectivity and activity such catalysts offer. By elucidating the synergistic effects between copper single atoms, water-derived reactive species, and light, researchers can now conceive tailored catalysts for a variety of hydrocarbon conversions previously limited by thermodynamic or kinetic constraints.
In conclusion, the photo-thermo catalytic system employing a copper single-atom catalyst under water vapor illumination inaugurates a new frontier in alkane dehydrogenation chemistry. It opens sustainable and energy-efficient avenues for producing vital chemical intermediates under mild, near-ambient conditions. By exploiting water as a catalytic medium and solar energy as a clean power source, this research points the way toward greener chemical manufacturing processes, aligning with international aspirations for sustainable industrial development and carbon neutrality in the decades to come.
Subject of Research: Not applicable
Article Title: Light-driven propane dehydrogenation by a single-atom catalyst under near-ambient conditions
News Publication Date: 21-Mar-2025
Web References:
References:
Zhang Tao, Wang Aiqin, Gao Yi, and colleagues, "Light-driven propane dehydrogenation by a single-atom catalyst under near-ambient conditions," Nature Chemistry, March 2025.
Image Credits: Dalian Institute of Chemical Physics (DICP)
Keywords
Catalysis, Dehydrogenation
