The role of effective catalysts for hydrogen production: A performance evaluation

In recent years, research on hydrogen (H 2 ) production for alternative and environmentally-benign energy solution as fuel, storage medium and feedstock has been one of the most highly demanded subjects. It aims to reduce the pressures set by carbon dioxide emissions and the depletion of fossil fuel supplies. Nevertheless, large-scale H 2 production is limited by its high cost and low yield. The distinct photo-electrochemical characteristics of catalysts have shown them to have great promise for enhancing the production of H 2 . This article presents an updated and comprehensive review of enhanced H 2 production using various catalysts in biological, thermochemical, and water-based processes. Various operational parameters (reactor configuration, catalyst dosage, catalyst type, catalyst modification methods, temperature, pH, and inoculum type) are summarized to improve the H 2 production performance and reduce the environmental impacts and costs of these processes. For instance, in dark fermentation, biological H 2 production is enhanced by 3.2–38 % with certain metal catalysts. Overall, results revealed that catalysts, specifically inorganic catalysts such as iron, nickel, titanium oxide, and silver, have improved the production rate of H 2 . This review has provided the application fields and working principles of catalysts in different H 2 production processes. Finally, we suggested the main concerns that need to be prioritized in the long-term advancement of H 2 production using catalysts. • Numerous effective catalysts are potentially considered to enhance hydrogen production. • An evaluation of the use of various catalysts is performed for H 2 production improvement. • Effects of using support materials on the stability of the catalyst are discussed with examples. • It is clear that Ni and Fe-based catalysts yield the highest H 2 production.