Deposition of highly dispersed gold nanoparticles onto metal phosphates by deposition–precipitation with aqueous ammonia†
An efficient method for depositing gold nanoparticles onto metal phosphate has been developed. Deposition–precipitation with aqueous ammonia enabled small gold nanoparticles to be deposited onto a series of metal phosphates with high dispersity and density. A detailed investigation of the mechanism of the formation of gold nanoparticles corroborated that strong interaction between a gold–ammine complex formed by the treatment of HAuCl4 with ammonia and positively-charged metal phosphates was responsible for the formation of highly dispersed gold nanoparticles. Furthermore, the thus-prepared gold catalysts supported on metal phosphates showed higher catalytic activity than those supported on metal oxides for the hydroamination of terminal alkynes.