NiCuCo2O4 Supported Ni–Cu Ion-Exchanged Mesoporous Zeolite Heteronano Architecture: An Efficient, Stable, and Economical Nonprecious Electrocatalyst for Methanol Oxidation

A unique strategy to obtain highly efficient electrocatalysts based on the spinel Ni0.5Cu0.5Co2O4 and mesoporous ZSM-5 (Zeolite Socony Mobil-5) is reported here for methanol oxidation in an alkaline medium. To develop an efficient catalyst, Ni2+–Cu2+ ion-exchanged mesoporous ZSM-5 and Ni0.5Cu0.5Co2O4 are prepared. 30 wt % of Ni0.5Cu0.5Co2O4 decorated Ni2+–Cu2+ ion-exchanged mesoporous ZSM-5 exhibits exceptionally higher catalytic activity with reasonably low onset potential than that of Ni0.5Cu0.5Co2O4, NiCo2O4, CuCo2O4, and Ni2+–Cu2+ ion-exchanged mesoporous ZSM-5. Electrochemical oxidation of HCHO and HCOOH also takes place over this catalyst at the same condition. The material exhibits high current density (21.4 mA/cm2) and stable electrocatalytic activity (with 99% retention) even after 1000 potential cycles. However, the benchmark catalyst Pt(20%)/C exhibits low activity (1.6 mA/cm2) and significant deactivation phenomenon (with 25% activity retention) at the identical condition. The cooperative contributions provided by Ni0.5Cu0.5Co2O4 and Ni2+–Cu2+ ion-exchanged mesoporous ZSM-5 support having Brönsted acidity, large external surface area, and intercrystalline mesoporosity deliver excellent electrocatalytic activity. The ease of synthesis, scale-up, stable and exceptional electrocatalytic activity paves the path toward the development of highly efficient alkaline direct methanol fuel cells.