Cu(OH)2-Ni(OH)2 engulfed by zeolite-Y hydroxyl nest and multiwalled carbon nanotube for effective methanol oxidation reaction

Abstract

Cu(OH)2-Ni(OH)2 supported on zeolite-Y and combined with multi-walled carbon nanotube (MWCNT), M(OH)2-Y-CNT (M = Cu, Ni) was found to be an excellent multicomponent hybrid system for methanol oxidation reaction (MOR). The formation of metal hydroxyl nest interconnected through MWCNT produced a high current density of 5.5 A/mg with significant durability up to 11.1 h. The electrochemical oxidation of methanol was found to be significant with maximum current density when the Cu:Ni ratio was 3:1. The surface hydroxyl group of zeolite-Y and -COOH functional group of MWCNT interacted strongly with Cu(OH)2 and Ni(OH)2 and provided a strong metal to surface interaction. From the temperature programme desorption (TPD) study and pyridine adsorption FTIR analysis, it was evident that both the acidity and basicity of Cu(OH)2-Ni(OH)2-Y catalyst was influenced by the MWCNT and consequently helped in MOR. Modification with MWCNT also lead to the change in the binding energy values of Cu and Ni and thereby effected the overall MOR activity of the electrocatalyst. The MOR activity of the hybrid material was tested by modifying the glassy carbon working electrode (GCE) as well in Pt working electrode. The MOR activity was found to be much better with Pt-electrode in comparison to GCE in terms of current density, durability and stability. The Pt-electrode modified with the hybrid M(OH)2-Y-MWCNT exhibited high CO tolerance in comparison to commercial Pt/ C electrocatalyst.