Selective catalytic reduction of NO by C2H2 over Ce-Al2O3 catalyst with rate-determining step of NO

• 作 者: Suhua Yan Xinping Wang Wenchen
• 机 构: State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116024, Liaoning, Ch
• 出 处: 天然气化学（英文版）
• 发表日期: 2012年3期
• 关键词: NOx removal NO oxidation nitrate species Ce-Al2O3 acetylene

Ce-Al2O3 catalysts prepared by co-precipitation are investigated both in NO oxidation by O2 and in selective catalytic reduction of NO by C2H2 (C2H2-SCR).It is found that C2H2-SCR is initiated and controlled by NO oxidation to NO2 over A12O3.Ce loading on Al2O3 is almost inactive for NO oxidation below 350 ℃,since NO2 strongly adsorbs on cerium oxide,leading to the active sites being blocked,which was characterized by temperature-programmed desorption of NO and NO2 and Fourier transform infrared spectroscopy after NO+O2 coadsorption over the samples.However,in the case of C2H2-SCR,Ce loading on Al2O3 significantly improves the reaction by accelerating the NO oxidation step in the temperature range of 250-450 ℃,since the nitrate species produced by NO2 adsorption is an active intermediate required by C2H2-SCR.