N掺杂对TiO_2负载Cu基催化剂甲醛乙炔化性能的影响

The influence of N doping on TiO_2 supported Cu-based catalyst for formaldehyde ethynylation

以TiO_2及N掺杂的TiO_2为载体、CuCl_2·2H_2O为铜源、NaOH为沉淀剂,采用沉积沉淀法制备了Cu含量(质量分数,下同)为30%的CuO/TiO_2及CuO/N-TiO_2催化剂。结合N_2物理吸附、XRD、XPS、H_2-TPR、CO-IR等表征,研究了N掺杂对TiO_2负载CuO催化剂结构及甲醛乙炔化性能的影响。结果表明,经N掺杂的TiO_2呈现出较多的Ti ^(3+)物种及氧空位,增加了CuO与载体间的相互作用,有利于CuO物种的分散。在炔化反应过程中,CuO原位转变为高分散的Cu^+活性中心,催化剂表现出高的催化活性与使用稳定性。

CuO/TiO2and CuO/N-TiO2catalysts with 30%Cu loading were prepared by deposition-precipitation method using copper chloride as copper source,sodium hydroxide as precipitant,and TiO2and N-TiO2as supports.Combined with the characterization of N2 physical adsorption-desorption,X-ray diffraction(XRD),H2-temperature programmed reduction(H2-TPR),X-ray photoelectron spectroscopy(XPS),CO Fourier transform infrared spectroscopy(CO-IR),and etc,the effects of N doping on the structure of TiO2supported CuO catalyst and the catalytic performance of formaldehyde ethynylation were studied.The results show that N-doped TiO2presented more Ti 3+species and oxygen vacant sites,which increased the interaction between CuO and the carrier and was conducive to the dispersion of CuO species.In the process of ethynylation,CuO is transformed into highly dispersed Cu+active species in situ,and the catalyst shows high catalytic activity and stability.