Coupling photochemical effects and photothermal conversion to boost hydrogen production from methanol steam reforming: Fundamentals, advances, and prospects

Abstract

Methanol steam reforming (MSR) represents a promising strategy for hydrogen-carbon co-cycling, and is acknowledged as one of the best solutions for addressing growing demands of hydrogen (H₂). However, the conventional MSR reactions are overly dependent on fossil fuels, confronting challenges of high energy consumption and carbon emissions. To this end, based on the insights of photochemical effects and photothermal conversion from green solar energy, photothermal MSR has appeared as a valuable technology. It enables powerful driving of MSR under mild conditions via the collaborative photothermal effects of photons and phonons, integrating the high-efficiency thermocatalysis and low-energy photocatalysis, thereby achieving the optimized form of energy utilization. Recently, such photothermal MSR has become a prominent and active research topic. This review seeks to offer a comprehensive summary of the advancements in this emerging field. Specifically, we present micro insights into the underlying mechanisms, and elucidate the fascinating photochemical effects in photothermal MSR reactions, highlighting the unique advantages of photothermal catalysis. Subsequently, the recent advances of photothermal MSR are systematically reviewed, especially the photothermal synergies and the mechanistic details that facilitate reactions. Moreover, the design and optimization of solar reactors is also summarized to advance the practicability of photothermal MSR. Finally, insights are offered into the future challenges and prospects. This review is expected to provide valuable reference for the exploitation of low-carbon H₂ production technologies.