Ni-Ag Supported on Reduced Graphene Oxide as Efficient Electrocatalyst for Alcohol Oxidation Reactions

Ni-Ag alloys supported on reduced graphene oxide (rGO) were investigated as electrocatalysts for the oxidation of ethanol, ethylene glycol, and glycerol. NiXAg100-X/rGO catalysts (X=0, 50, 66, 75, and 100) were prepared by the chemical reduction method, using sodium borohydride (NaBH4) as a reducing agent. The experimental results showed that the Ni-Ag alloys supported on rGO presented a better electrocatalytic activity compared to monometallic Ni(OH)(2)/rGO. Furthermore, the highest catalytic activity among the synthesized materials was observed for the Ni66Ag34/rGO ratio, which presented the highest peak current densities associated with the electrooxidation of ethanol (43.3 mA cm(-2)), ethylene glycol (60.6 mA cm(-2)), and glycerol (62.9 mA cm(-2)). The obtained values were, respectively, 1.7, 1.8, and 1.5 times higher compared to Ni(OH)(2)/rGO. The recorded chronoamperometric curves confirm the stability of the catalyst. The catalytic rate constants of Ni66Ag34/rGO were calculated for ethanol (8.84 x 10(4) cm(3) mol(-1) s(-1)), ethylene glycol (1.43 x 10(5) cm(3) mol(-1) s(-1)), and glycerol (1.0 x 10(5) cm(3) mol(-1) s(-1)).

Automated summary

Ni-Ag alloys supported on reduced graphene oxide (rGO) were investigated as electrocatalysts for the oxidation of ethanol, ethylene glycol, and glycerol. Among the synthesized materials, Ni66Ag34/rGO showed the best catalytic activity with the highest peak current densities for the electrooxidation of ethanol, ethylene glycol, and glycerol.