Catalyst design for microwave-enhanced hydrogen production: Comparative performance across diverse feedstocks

Microwave-driven dehydrogenation is gaining significant attention for its unique ability to achieve high conversion rates, exceptional selectivity in C-H bond cleavage, and rapid reaction kinetics. Here, we present the development and application of microwave-initiated heterogeneous processes for hydrogen production using diverse feedstocks such as biomass, methane (CH 4 ) and carbon dioxide (CO 2 ), waste plastics, and aliphatic and aromatic hydrocarbons. By purpose-designing microwave-active catalysts, we have established efficient pathways to convert renewable feedstocks and waste materials into hydrogen fuel. Ni-based catalysts, promoted with transition metals like Fe, Co, and Mg, were employed for low-temperature biomass gasification, achieving remarkable performance with rapid completion and high selectivity. Specifically, NiFeAlO x catalysts delivered superior gas yield (87.7%) and syngas selectivity (93.7%), with an optimized H 2 /CO ratio near 2.0 that is suitable for Fischer-Tropsch process. Two greenhouse gases, CH 4 and CO 2 , were converted into syngas (CO + H 2 ) via methane dry reforming (MDR), using NiMn/ZrO 2 catalysts. The process achieved outstanding CH 4 and CO 2 conversions of over 88% and 94%, respectively, sustained for more than 10 hours. High purity hydrogen and high-quality carbon nanotubes (CNTs) were produced by dehydrogenation of waste plastics using iron-based catalysts. Further study on the dehydrogenation of aliphatic and aromatic compounds achieved a 90% hydrogen selectivity and up to 94% CO 2 emission reduction. These findings demonstrate the potential of microwave-driven catalytic processes as efficient, sustainable approaches to carbon-neutral technologies. By optimizing conversion efficiency, promoting waste valorization, and advancing the circular economy, this work underscores the transformative impact of microwave-driven methods on hydrogen production and sustainable energy solutions. • Microwave-driven heterogeneous catalysis offers an innovative approach for the dehydrogenation of diverse resources, enabling efficient hydrogen production. • Hydrogen-rich waste materials, such as plastics, biomass, and biogas, can be rapidly dehydrogenated using microwave catalysis, unlocking a sustainable energy source. • Ni-based catalysts demonstrate outstanding catalytic performance under microwave conditions, selectively cleaving C-H bonds with high efficiency. • Microwave-driven dehydrogenation achieves exceptional selectivity and energy efficiency while minimizing CO 2 emissions, promoting greener hydrogen production. • This cutting-edge technology using microwave has the potential to revolutionize hydrogen production and accelerate the development of low-carbon energy solutions.