Green Hydrogen Economy: A Bibliometric Analysis

Abstract

This study presents a bibliometric analysis of research on the green hydrogen economy to map its intellectual structure, thematic evolution, and collaboration patterns. A total of 121 Scopus-indexed documents published between 2006 and 2026 were analyzed using VOSviewer through keyword co-occurrence, citation, co-authorship, institutional, and country-level networks. The results show that the field is organized around “hydrogen economy,” “hydrogen production,” and “green hydrogen,” which form five interrelated clusters covering hydrogen production technologies and emissions, renewable energy integration, economic and policy frameworks, decarbonization and techno-economic assessment, and energy systems. The overlay map indicates a thematic shift from technology- and resource-oriented topics toward life cycle, carbon economy, public policy, energy transition, and green development issues in the most recent period. Citation analysis reveals that the most influential works address carbon-neutral hydrogen pathways, the role of green hydrogen in a renewable energy society, water constraints, and electrolysis catalysts. Collaboration networks remain small and cohesive, led by a Nigerian author group centered on Ajiboye and a multinational institutional group linked to Vietnam, while India, China, Germany, Australia, and the United States emerge as leading countries. The findings offer a reference for researchers and policymakers in directing future studies toward integrated techno-economic, environmental, and governance perspectives on the green hydrogen economy.