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In this paper, we report an efficient strategy for the synthesis of Cu/Co double-doped CeO 2 nanospheres (Cu x Co 1- x -CeO 2 -Pt, 0 ≤ x ≤ 1), which were fabricated via a simple water-glycol system. The following in situ surface decoration of Pt nanoparticles make these nanospheres highly active for the catalytic reduction of nitrophenol and CO oxidation. Detailed tests show that their catalytic performance strongly depends on the doping components and ion concentration of Cu and Co ions. The best samples of Cu 0.50 Co 0.50 -CeO 2 -Pt and Cu 0.34 Co 0.66 -CeO 2 -Pt demonstrate an excellent turnover frequency (TOF) of more than 450 h -1 after five cycles and retains about 99% conversion by using NH 3 BH 3 as a reductant to reduce nitrophenol. Moreover, Cu 0.50 Co 0.50 -CeO 2 -Pt possesses a much lower light-off and T 100 (the temperature for 100% CO oxidation) temperature compared with the other catalysts.

A galvanic replacement strategy has been successfully adopted to design Ag x Au 1- x @CeO 2 core@shell nanospheres derived from Ag@CeO 2 ones. After etching using HAuCl 4 , the Ag core was in situ replaced with Ag x Au 1- x alloy nanoframes, and void spaces were left under the CeO 2 shell. Among the as-prepared Ag x Au 1- x @CeO 2 catalysts, Ag 0.64 Au 0.36 @CeO 2 shows the optimal catalytic performance, whose catalytic efficiency reaches even 2.5 times higher than our previously reported Pt@CeO 2 nanospheres in the catalytic reduction of 4-nitrophenol (4-NP) by ammonia borane (AB). Besides, Ag 0.64 Au 0.36 @CeO 2 also exhibits a much lower 100% conversion temperature of 120 °C for catalytic CO oxidation compared with the other samples.