Integrating Catalysis of Methane Decomposition and Electrocatalytic Hydrogen Evolution with Ni/CeO₂ for Improved Hydrogen Production Efficiency

Ni/CeO 2 enables either methane decomposition or water electrolysis for pure hydrogen production. Ni/CeO 2 , prepared by a sol–gel method with only one heat treatment step, was used to catalyze methane decomposition for the generation of H 2 . The solid byproduct, Ni/CeO 2 /carbon nanotube (CNT), was further employed as an electrocatalyst in the hydrogen evolution reaction (HER) for H 2 production. The Ni/CeO 2 catalyst exhibits excellent activity for methane decomposition because CeO 2 prevents carbon encapsulation of Ni nanoparticles during the preparation process and forms a special metal–support interface with Ni. The derived CNTs act as antenna to improve conductivity and promote the dispersion of agglomerated Ni/CeO 2 . In addition, they provide H 2 diffusion paths and prevent Ni/CeO 2 from peeling off the HER electrode. Although long‐term methane decomposition reduces the HER activity of Ni/CeO 2 /CNTs (owing to degradation of the delicate Ni/CeO 2 interface), the tunable nature of the synthesis makes this an attractive sustainable approach to synthesize future high‐performance materials.