Jian Fang,Zhi-Hong Ma,Jing-Jing Xue,Xi Chen,Rong-Pu Xiao,Ji-Ming Song
Precious metals doping can greatly change the gas sensing performance of semiconductor metal oxide . Herein, the Au-doped In 2 O 3 nanoparticles (NPs) were prepared via a combination solvothermal and liquid-phase reduction method, and the obtained nanoparticles were characterized by various techniques. The results indicated that Au nanocrystals with a diameter ca. 5 nm were uniformly distributed on the surface of the irregular In 2 O 3 NPs. Importantly, compared with undoped In 2 O 3 , the specific surface area of all the Au-doped In 2 O 3 NPs increased. And all the Au-doped In 2 O 3 sensors greatly improved the gas sensing performance towards ethanol. The optimal operating temperature reduced from 240 °C for undoped In 2 O 3 to 200 °C for Au-doped In 2 O 3 . Of them, the 4 wt% Au-doped In 2 O 3 sensor displayed highly response (106 towards ethanol at 100 ppm) at the optimal operating temperature, good linear coefficient, high reproducibility, and long-term stability towards ethanol. Moreover, through the detection of seven gases including ethanol, such as methanol, acetone , benzene, formaldehyde, isopropanol, and nitrogen dioxide， we found that the fabricated sensor based on 4 wt% Au-doped In 2 O 3 had good selectivity towards ethanol. Finally, the mechanism of the excellent performance of the 4 wt% Au-doped In 2 O 3 sensor for ethanol was explained.
Platinum-based electrocatalysts represent the most promising candidates for the methanol oxidation reaction (MOR) in direct methanol fuel cells. However, the wide commercialization of platinum-based electrocatalysts faces significant challenges, including high material costs, insufficient catalytic activity, limited operational durability, and susceptibility to CO poisoning. To overcome these issues, a new Au-doped Pt-Co aerogel (AG) is fabricated by the facile one-pot aqueous-solution heteroatom doping method. This catalyst demonstrates good electrocatalytic performance for MOR, combining both high activity and remarkable stability. The Au 1 -Pt 67 Co 33 AG with optimized Au doping amount exhibits outstanding mass activity, which is 1.7 times that of its undoped Pt 67 Co 33 AG counterpart and 4.6 times that of the commercial Pt/C catalyst. Furthermore, the Au 1 -Pt 67 Co 33 AG demonstrates significantly enhanced long-term stability under continuous operation. Density functional theory calculations indicate that Au doping reduces the energy barriers for methanol dehydrogenation and lowers the total energy barriers for the *CO oxidation steps, facilitating the rapid dehydrogenation of CH n OH and faster conversion of *CO, thereby significantly enhancing the electrocatalytic activity and stability of the Au 1 -Pt 67 Co 33 AG toward MOR.
危险品化学品经营许可证（带存储）