NaCl-induced nickel-cobalt inverse spinel structure for boosting hydrogen evolution from ethyl acetate and water

The proper design of an NaCl-induced nickel-cobalt inverse spinel structure is reported as a promising catalyst for boosting H ₂ evolution from the energy benign sources of ethyl acetate and water. The designed NiCo _0.5 O _y /NaCl catalyst exhibits the optimal performance with ∼100% EA conversion, 88.1% H ₂ selectivity and high stability during autothermal reforming at 650 °C and achieves a very high H ₂ selectivity of 96.3% at 600 °C by accelerating the water-gas shifting reaction (the rate-determining step). The multiple (Ni _x Co _1-x )(Ni _y Co _2-y )O ₄ inverse spinel structures play significant roles in the enhanced catalytic performance. Benefiting from the unique advantages of (i) stable inverse spinel structures, (ii) abundant domains and defects, (iii) abnormal Ni ²⁺ /Ni ³⁺ (0.36) and Co ²⁺ /Co ³⁺ (3.03) ratios, and (iv) rich redox ability, the catalyst possesses high adsorption capacity towards EA and H ₂ O, abundant active sites and fast electron exchange ability between the reactants and the catalyst. Consequently, the catalyst exhibits a highly efficient and robust hydrocarbon fuel reforming performance. These findings will lead to the development of novel catalysts based on inverse spinels for hydrogen production applications.