Effective polymer decoration on nickel-imine complex to enhance catalytic hydrogen evolution

Abstract

Since fossil fuels are rapidly depleting, finding alternative energy sources is becoming increasingly important. Among these alternatives, hydrogen (H2) is the most viable option. In hydrogen evolution systems, supported metal catalysts enhance the catalytic activity in the hydrolysis reaction by increasing the surface area. Therefore, this research focuses on preparing three different polymer-decorated Nickel-Imine complex catalysts (Ni@EC, Ni@EC-250, Ni@ECM) to improve their efficiency. To achieve the catalysts, a Nickel-Imine complex [1] was supported on three different polymers (EC, EC-250, and ECM). The catalysts (Ni@EC, Ni@EC-250, Ni@ECM) were then utilized to generate hydrogen from NaBH4 hydrolysis. The hydrogen evolution rates for Ni@EC, Ni@EC-250, and Ni@ECM catalysts were found as 6879; 15576; 8830 and 15459; 28689; 23417 mL H2 gcat-1.min-1, respectively at 30 oC and 50 oC. Results indicate that the Ni@EC-250 catalyst exhibited the best activity. Consequently, the subsequent steps of the catalytic hydrolysis reaction were studied using Ni@EC-250. The activation energy of the Ni@EC-250 catalyst was estimated at 39.255 kJ.mol-1. The reusability tests demonstrate that Ni@EC-250 remains active in sodium borohydride hydrolysis even after five runs. Technical abbreviations are defined upon first use. This study elucidates the reaction mechanism and kinetic data of catalytic sodium borohydride hydrolysis at various temperatures.