Toward efficient, low-carbon, and Cost-effective hydrogen production shifting from fossil fuel-based to renewable water electrolysis: A perspective and outlook

With global efforts to reduce carbon emissions speeding up and the quest for sustainable energy, hydrogen has become a highly promising zero‑carbon energy option. This review systematically assesses mature and rapidly developing hydrogen production technologies—including Fossil fuel-based processes, industrial by-product recovery, and water electrolysis methods, analyzing them from the perspectives of efficiency, carbon emissions, and cost. We compare technical principles and performance metrics of leading technologies such as steam methane reforming (SMR, 0.8–6 $/kg), coal gasification (11–25 kg CO2/kg), and advanced electrolysis systems like PEM, AEM, and SOEC (e.g.,3.6 kWh/Nm3), highlighting their respective maturity, environmental footprints, and scalability. Our analysis emphasizes that while Fossil fuel-based methods currently dominate due to cost advantages, their sustainability hinges on CCUS integration. In contrast, By-product hydrogen presents a low-carbon, cost-effective interim solution. Water electrolysis powered by renewables holds the greatest long-term promise, but remains constrained by high cost (up to 7 $/kg) and technological barriers. We identify key technical bottlenecks—including catalyst degradation and membrane instability—that must be addressed via innovations in materials, integration, and renewable coupling. By presenting a structured comparison of current and emerging hydrogen production technologies, this review offers clear guidance for targeted innovation and provides actionable insights for researchers, policymakers, and industry stakeholders to accelerate the development of cost-competitive, low-emission hydrogen production systems aligned with global climate goals.