Effect of chemical corrosion and alloying on the catalytic activity of 18 carat gold for the electro-oxidation of HCOOH

The catalytic activity of original and corroded Au54–0.7xCu28–0.3xAg18–2x(Ni2Zn)x (x = 0, 3, 6 and 9) alloys, together with their structure, hardness and morphology, are studied using various techniques. Alloying improves the hardness of the samples. There are some Ag/AgCl species on the surfaces of corroded samples. Chemical corrosion changes the surface orientation of the Au-rich solid solution, which is related to the rearrangement of Au atoms to accommodate surface defects. The surface orientation change and presence of Ag/AgCl increase the catalytic activity of the samples for the electro-oxidation of HCOOH. [Display omitted] •Alloying increases the hardness of samples.•Chemical corrosion can change the surface orientation of Au based catalyst.•Ag/AgCl species increase electro-oxidation of HCOOH.•Catalytic activities of Au based catalysts can be regulated by chemical corrosion and alloying.