Blue Hydrogen Research Surges as Scientists Map a Fast-Growing Field

Blue hydrogen, made from natural gas with carbon capture and storage, has moved from the margins of energy research to one of its fastest-growing corners. A new scientometric review published in Discover Energy traces that rise by analyzing 1,432 publications indexed in the Web of Science Core Collection between 2000 and 2025.

The team screened an initial 1,491 records down to 1,432 articles and review articles, using the keyword phrase “blue hydrogen production” in the abstract field and restricting the search to English-language publications. They then processed the dataset with three complementary tools: the Bibliometrix package in R for performance indicators and trend topics, VOSviewer version 1.6.20 for co-authorship and keyword co-occurrence networks, and CiteSpace for cluster and timeline analysis. Together, the analyzed papers have accumulated 42,065 citations, an average of 29.38 citations per article, and an h-index of 92, signals the authors interpret as substantial impact for a still-young field.

The temporal picture divides cleanly into three phases. Between 2000 and 2010, publication activity was limited and dominated by chemistry-oriented studies. From 2010 to 2020, the field expanded into catalytic processes, environmental engineering, and the integration of carbon capture. After 2020, the review identifies an interdisciplinary, deployment-oriented phase marked by rapid publication growth, sustainability assessment, techno-economic analysis, renewable integration, and policy studies. Annual output climbed from roughly fifty papers per year in the expansion phase to a peak of about 270 publications in the most recent period, with the cumulative total surpassing 1,400 by 2024. The authors calculate an average annual growth rate of 17.6 percent since 2015.

Geographically, the field is heavily concentrated. China leads with 472 articles, 12,234 citations, and the highest country-level h-index of 55. The United States follows with 190 articles, India with 133, and South Korea with 107. Those four countries together account for 63 percent of the publications in the dataset. A second tier includes the United Kingdom with 75 papers, Saudi Arabia with 72, and Germany with 58, while Canada, Italy, Japan, France, Australia, Brazil, Iran, Malaysia, Egypt, and Pakistan each fall in the 26-to-50 range. In total, 92 countries have contributed since the start of the century, a spread the authors read as evidence that blue hydrogen has become a shared international research priority rather than a niche interest of a few wealthy nations.

Citation patterns reveal a familiar bibliometric dynamic. In the early 2000s, average citations per article were high and irregular because few papers existed and older work had more time to accumulate references. As output surged, per-article averages moderated, and from 2020 onward they declined even as total publications soared. The h-index, by contrast, reached its strongest sustained levels in the last five years. The authors caution that the recent combination of high output and a per-paper citation dip likely reflects short citation windows rather than weaker research, and that the picture could look different when revisited later.

At the institutional level, the Chinese Academy of Sciences dominates with 50 publications, 2,010 citations, and an h-index of 20. The Egyptian Knowledge Bank ranks second with 27 articles, followed by the Indian Institute of Technology System with 24 and the Council of Scientific and Industrial Research with 23. The University of California System stands out for high citation impact per article despite fewer publications. Network analysis of betweenness centrality adds a second dimension: institutions such as Harvard University, the Helmholtz Association, the U.S. Department of Energy, and Spain’s CSIC publish fewer papers but occupy structurally central positions, connecting otherwise separate research communities. The authors frame this as two complementary routes to influence, publication scale and strategic network positioning.

Keyword mapping exposes the field’s intellectual structure. In a broad co-occurrence analysis with a minimum of 20 occurrences, VOSviewer visualized 287 of 478 qualifying keywords in three clusters: a red cluster of 110 terms centered on photocatalysis, nanomaterials, and water splitting; a green cluster of 109 terms covering hydrogen energy systems, cost, policy, economy, and electrolysis; and a blue cluster of 68 terms tied to biological and chemical processes such as hydrogen peroxide and enzymatic activity. A narrower query restricted to publications explicitly linking blue hydrogen production with carbon capture, 166 articles in all, produced a tightly focused map dominated by production, capture, CCS, electrolysis, and cost, underscoring how directly the field ties decarbonization to capture rates and system-level implementation.

The review situates these bibliometric findings against deployment data from the International Energy Agency. Global hydrogen production rose from 90 million tons in 2020 to more than 100 million tons in 2025, yet low-emission hydrogen still supplies less than 1 percent of the total and contributed to roughly 980 million tons of CO2 emissions from fossil-based production in 2024. About 15 fossil fuel-based hydrogen facilities currently use CCS, capturing around 12 million tons of CO2 annually while producing 0.9 to 1.2 million tons of hydrogen. Low-emission hydrogen production with CCS is projected to grow from 0.6 million tons in 2023 to roughly 11 million tons annually by 2030, and global blue hydrogen capacity is projected to reach 5 million tons per year by 2030, with about 80 percent of those projects in Europe and 15 percent in Canada. Under the IEA net-zero pathway, steam methane reforming with CCS could reach 10 to 15 million tons in 2030 and roughly 200 million tons by 2050.

Technically, the review notes that steam methane reforming remains the dominant blue hydrogen route, capable of capturing up to 90 percent of CO2, with about 60 percent of emissions available in concentrated streams for efficient capture. Autothermal reforming can capture 95 to 99 percent, while partial oxidation and coal gasification reach 90 to 95 percent. The authors argue that production cost cannot be separated from capture efficiency, energy consumption, compression, transport, and storage, and that environmental performance must be judged across full system boundaries including upstream methane leakage, not just plant-level capture rates. They position blue hydrogen as a transitional pathway whose long-term role depends on improved capture performance, controlled methane emissions, viable infrastructure, and competitiveness with green hydrogen, which currently costs about USD 3.00 to 8.00 per kilogram and is projected to fall to USD 1.00 to 3.50 by 2030.

The authors are candid about limitations. The Web of Science Core Collection may not cover all relevant publications, author name variations and affiliation inconsistencies can distort productivity assessments, and the study identifies major research challenges without establishing their relative importance. They suggest future work integrate multiple databases and apply expert-based multi-criteria decision-making to prioritize the field’s obstacles. Still, the overall trajectory is clear: a field that barely existed before 2010 has consolidated into a mature, interdisciplinary, deployment-oriented research enterprise, with emerging frontiers in supply chain decarbonization, methane leakage, infrastructure planning, and carbon credit mechanisms shaping the next phase of the global low-carbon hydrogen debate.

Subject of Research: A bibliometric analysis of global blue hydrogen production research trends, collaboration networks, and thematic evolution from 2000 to 2025.

Article Title: A scientometric review of blue hydrogen production

Article References: Romel, M., Kabir, G., & Haq, B. (2026). A scientometric review of blue hydrogen production. Discover Energy, 6(1), Article 87. https://doi.org/10.1007/s43937-026-00203-x

Image Credits: AI Generated

DOI: 10.1007/s43937-026-00203-x

Keywords: blue hydrogen, carbon capture and storage, scientometrics, bibliometric analysis, steam methane reforming, hydrogen production, energy transition, life-cycle assessment, research collaboration, Web of Science, decarbonization, techno-economic analysis