气氛条件对Pt-Mo_2C催化剂脱硝性能的影响

Effects of atmosphere conditions on catalytic de-NO_x performance of Pt-Mo_2C catalysts

采用程序升温碳化、等体积浸渍等方法制备不同的Pt-Mo_2C催化剂,考察催化剂的催化脱硝性能。采用X线衍射仪(XRD)、比表面积测试仪、扫描电子显微镜(SEM)、X线光电子能谱仪(XPS)等手段表征催化剂的物理化学性能。以H_2作为催化反应还原剂,在不同n(H_2)/n(NO)及无氧或富氧条件下测试Pt-Mo_2C的催化脱硝性能。结果表明:相比于掺杂Pt元素的Mo_2C催化剂,直接负载氯铂酸钾的Mo_2C催化剂效果最好,在无氧条件下n(H_2)/n(NO)=1和5时,NO的转化率最高分别可达到60.3%和100%,富氧条件下NO的转化率最高分别可达到40.1%和92.1%。富氧条件降低了催化剂的催化性能,而较高的n(H_2)/n(NO)有利于提升NO的转化率并拓宽反应温度区间。

The de-NOxperformance over Pt-Mo2C catalysts prepared by temperature programmed carbonization and equal volume impregnation was investigated.The physicochemical properties of catalysts were characterized by X-ray diffraction（ XRD）,specific surface area measurement,scanning electron microscopy（ SEM） and X-ray photoelectron spectroscopy（ XPS）. H2 was used as the reducing agent for the catalyzed denitrification reaction. The factors such as n（ H2）/n（ NO）,the presence or absence of oxygen were studied. Results indicated that the Pt loaded Mo2C catalyst had the better catalytic performance than Pt doped Mo2C catalyst. The NO conversion with n（ H2）/n（ NO） = 1 and 5 were respectively 60. 3% and 100% without oxygen,while 40. 1% and 92. 1% on the condition of excess oxygen.The aerobic conditions could reduce the performance of the catalyst,while the higher n（ H2）/n（ NO） could increase the NO conversion and broaden the active temperature range.