纳米二氧化钛负载的铜钴氧化物上一氧化碳催化还原一氧化氮。

Catalytic reduction of nitric oxide with carbon monoxide on copper-cobalt oxides supported on nano-titanium dioxide.

机构信息

Department of Environmental Engineering, Xiangtan University, Xiangtan 411105, China.

出版信息

J Environ Sci (China). 2009;21(9):1296-301. doi: 10.1016/s1001-0742(08)62418-3.

PMID:19999980

Abstract

A series of copper-cobalt oxides supported on nano-titanium dioxide were prepared for the reduction of nitric oxide with carbon monoxide and characterized using techniques such as XRD, BET and TPR. Catalyst CuCoOx/TiO2 with Cu/Co molar ratio of 1/2, Cu-Co total loading of 30% at the calcination temperature of 350 degrees C formed CuCo2O4 spinel and had the highest activity. NO conversion reached 98.9% at 200 degrees C. Mechanism of the reduction was also investigated, N2O was mainly yielded below 100 degrees C, while N2 was produced instead at higher temperature. O2 was supposed to accelerate the reaction between NOx and CO for its oxidation of NO to give more easily reduced NO2, but the oxidation of CO by O2 to CO2 decreased the speed of the reaction greatly. Either SO2 or H2O had no adverse impact on the activity of NO reduction; however, in the presence of both SO2 and H2O, the catalyst deactivated quickly.

摘要

一系列负载在纳米二氧化钛上的铜钴氧化物被制备出来，用于一氧化碳还原一氧化氮，并采用 XRD、BET 和 TPR 等技术进行了表征。在煅烧温度为 350℃、Cu/Co 摩尔比为 1/2、Cu-Co 总负载量为 30%的条件下，形成了具有最高活性的 CuCo2O4尖晶石的 CuCoOx/TiO2 催化剂。在 200℃时，NO 的转化率达到了 98.9%。还研究了还原的机理，N2O 主要在低于 100℃时生成，而在较高温度下则生成 N2。O2 被认为可以加速 NOx 和 CO 之间的反应，因为它将 NO 氧化为更容易还原的 NO2，但 O2 将 CO 氧化为 CO2 会大大降低反应速度。SO2 或 H2O 对 NO 还原活性没有不利影响；然而，在同时存在 SO2 和 H2O 的情况下，催化剂会迅速失活。