Recent Advances in Catalysts for Hydrogen Production: From Fossil-Derived Processes to Sustainable Water Electrolysis and Photocatalysis.

This review provides a thorough summary of recent progress in catalysts used for hydrogen production. It starts with an overview of the importance of hydrogen and its historical background, then looks into catalytic methods for the thermochemical transformation of fossil fuels and organic materials, with a specific emphasis on steam methane reforming (SMR) and ethanol steam reforming (ESR). The review discusses the fundamental processes and approaches to minimize CO2 emissions and tackle catalyst deactivation due to sulfur and coking. It also delves into dry reforming and the catalytic breakdown of methane. Furthermore, the review investigates water splitting through electrolysis and photolysis, clarifying key principles, types of catalysts, reaction pathways, and performance assessment criteria. A specific section focuses on biological, biomimetic, and bioinspired catalytic-driven methods for generating hydrogen, along with a brief overview of catalysts involved in hydrogen release from chemical hydrides. Ultimately, the review underscores the increasingly important role of computational techniques, such as density functional theory (DFT) and Artificial Intelligence/Machine Learning (AI/ML), in the rational design of innovative catalytic materials. While acknowledging the extensive field of hydrogen production, this review seeks to offer an insightful perspective on catalytic elements, highlighting current trends, challenges, and future opportunities in the pursuit of sustainable hydrogen generation. The final remarks stress the importance of developing practical and scalable catalysts, taking environmental impacts into account, standardizing the reporting of catalytic performance, and recognizing the significant role often played by catalyst supports.