Jiali Sheng,Jiahui Kang,Zhixiong Hu,Yan Yu,Xian-Zhu Fu,Rong Sun,Ching-Ping Wong
Exploring effective electrocatalysts is in urgent demand to boost their large-scale applications for direct ethanol fuel cells. Herein, for the first time, we report nanoparticle-assembled Pd nanocages with efficient catalytic activity towards ethanol electrochemical oxidation. The catalysts are prepared from the second template of a nanosheet surface of amorphous Co(OH)2 octahedral nanocages, which are prepared from the original template of octahedral Cu2O. These Pd octahedral nanocages exhibit a porous rough surface, which consists of smaller Pd nanoparticles, endowing them with highly active surface area and many active sites. For the electrochemical oxidation of ethanol, the Pd nanocages demonstrate superior activity (3765 mA mgPd−1), 4.8 times and 5.9 times those of commercial Pd/C and Pd nanocatalysts, respectively, prepared directly from an octahedral Cu2O original template. Furthermore, the Pd nanocages demonstrate excellent long-term durability.
Yishan Jiang,Ying Xu,Qichao Zhang,Xin Zhao,Feng Xiao,Xinbo Wang,Guojun Ma
Nowadays, it is highly desired to develop highly active and humidity-resistive ozone decomposition catalysts to eliminate the ozone contaminant, one of the primary pollutants in the air. In this work, a series of Cu2S hollow structured materials were rapidly synthesized using different structured Cu2O templates. The Cu2S from porous Cu2O showed the highest ozone catalytic decomposition efficiency of >95% to 400 ppm ozone with a weight hourly space velocity of 480,000 cm3·g−1·h−1in dry air. Importantly, the conversion remained >85% in a high relative humidity of 90%. The mechanism was explored by diffusive reflectance infrared spectroscopy which showed the decomposition intermediate of O22−, and X-ray photoelectron spectroscopy revealed the dual active site of both Cu and S. The EPR and UPS characterization results also explained the superiority of porous Cu2S catalysts from the material itself. All these results show the effective decomposition of ozone by Cu2S, especially in harsh environments, promising for active ozone elimination.