Mapping emerging trends in hydrogen fuel cell technology for sustainable transportation: Insights from bibliometric and topic modeling analyses

Hydrogen fuel cell (HFC) technologies have emerged as a key pathway toward low-carbon mobility, prompting rapid growth in related research. This study provides a structured bibliometric and topic-modeling analysis of 364 Scopus-indexed journal articles published between 2020 and 2025 to examine recent developments in HFC-based sustainable transportation. A dual-stage methodological framework combining bibliometric indicators and Latent Dirichlet Allocation (LDA) was employed to address research output trends, keyword evolution, and latent thematic structures. The results indicate sustained publication growth and increasing concentration around system-level optimization and hybrid fuel cell–battery integration. Control strategies and intelligent energy management frameworks dominate the current research landscape, while renewable coupling, infrastructure coordination, and power electronic integration are gaining visibility. Temporal analysis reveals a shift from component-level investigations toward integrated, digitally enabled mobility systems. The contribution of this study lies in its domain-specific application of machine learning–assisted bibliometric mapping to hydrogen fuel cell transportation, providing a data-driven synthesis of thematic evolution and cross-domain integration patterns. The findings offer structured insights for future research directions in degradation-aware control, infrastructure–vehicle coordination, and subsystem standardization within contemporary hydrogen mobility research.