Policy-driven innovation pathways for strategic green technologies: The case of hydrogen and carbon capture, utilization, and storage (CCUS) in South Korea

South Korea has positioned hydrogen and carbon capture, utilization and storage (CCUS) as key technological pillars of its 2050 carbon neutrality strategy. Despite sustained and ambitious policy intervention, however, empirical evidence on how policy interventions have reshaped public R&D portfolios and early industrial diffusion remains limited. This study examines hydrogen and CCUS in South Korea through a policy−R&D−industrial diffusion framework, focusing on policy sequencing and institutional design. The analysis combines qualitative content analysis with project-level R&D data from the National Science and Technology Information Service (NTIS) and interrupted time series analysis to identify policy-induced structural breaks, while industrial diffusion is assessed using deployment indicators such as hydrogen vehicles, hydrogen refueling stations, and large-scale (>100,000 tons/year) CCUS projects. The results indicate a clear divergence in policy outcomes between the two sectors. Hydrogen policy interventions rapidly shifted public R&D toward utilization and industry-oriented development stages and were accompanied by a sharp increase in public R&D expenditures, thereby accelerating deployment. By contrast, CCUS experienced fragmented R&D adjustments, continued public-sector dominance, and limited large-scale demonstration. These findings highlight that while policy-driven, mission-oriented innovation pathways can mobilize R&D and early markets, their effectiveness depends on timely legal frameworks, the institutional coherence of the policy framework, and market-supporting infrastructure. In the case of CCUS, delayed legal institutionalization has constrained the transition from public R&D accumulation to industrial-scale deployment, highlighting the need for stronger regulatory clarity, market-creation instruments, and supporting data infrastructures.