Ionic Liquids-Based Iron Phosphide/Carbon Nanotubes Composites: High Active Electrocatalysts towards Hydrogen Evolution Reaction

摘要

New catalyst for hydrogen generation by water electrolysis in aqueous acid is made by mixing N,N-bis(4- (methoxycarbonyl)- benzyl)-N-methyl-d-glucaminium bromide (MBMGBr) and trichloroferrate (III) to form the iron containing ionic liquid (IL), MBMG-FeCl3Br. This IL is mixed with carbon nanotubes (CNTs) and sodium hypophosphite (NaH2PO2) and then heated to 300 oC in an inert atmosphere to give the final catalyst, a CNTsupported iron phosphide (FePMBMG/CNT), which exhibits catalytic activity toward hydrogen evolution reaction in 0.5 M aqueous sulfuric acid electrolyte with a low onset overpotential of 70 mV, a Tafel slope of 75.9 mV dec1, 95% Faradaic efficiency (FE) and current densities of 10 and 20 mA cm2, at overpotentials of 155 and 195 mV respectively, for a catalyst loading of 100 mg on 0.2 cm2 of glassy carbon electrode in which the IL to CNTs amount ratio is 1:1.