Novel promoting effects of cerium on the activities of NO_x reduction by NH_3 over TiO_2-SiO_2-WO_3 monolith catalysts

A series of catalysts were prepared by doping different loadings of CeO2 over TiO2-SiO2-WO3 and used for the selective catalytic reduction of NOx by NH3. The experimental results showed that the selective catalytic reduction（SCR） performance and SO2-resistant ability of TiO2-SiO2-WO3 were greatly enhanced by the introduction of cerium. The catalyst containing 10% CeO2 showed the highest NO conversion in a wide temperature range and good N2 selectivity with broad operation temperature window at the gas hourly space velocity（GHSV） of 30000 h–1, which was a very promising catalyst for NOx abatement from diesel engine exhaust. The catalysts were characterized by X-ray diffraction（XRD）, scanning electron microscopy with energy dispersive X-ray spectroscopy（SEM-EDS）, N2 adsorption-desorption（BET） and X-ray photoelectron spectroscopy（XPS）. The characterization results showed that the bigger pore radius, higher surface atomic concentration and dispersion of Ce and the abundant adsorbed oxygen on the surface of catalyst contributed to the best NH3-SCR performance of CeO2/TiO2-SiO2-WO3 catalyst containing 10% CeO2.     

灰分对蜂窝活性炭性能的影响

采用恒温搅拌法和恒温超声波振荡法酸解神府煤的灰分,通过电子万能材料试验机和BET分析了灰分对蜂窝活性炭机械性能和吸附性能的影响。实验结果表明,恒温超声波振荡法酸解灰分的效果好,组成灰分的无机盐对蜂窝体机械性能的提高具有促进作用,但对其吸附性能的提高则有阻碍作用。     

碳捕获与封存技术综述

人类活动排放的二氧化碳将导致全球温度上升,从而引发各种灾难。CCS是短期内减缓全球变暖速度的重要手段。文中综述了碳捕获和碳封存的技术方法,以及CCS技术存在的问题。碳捕获分为燃烧前捕获、富氧燃烧捕获和燃烧后捕获。碳封存方式有地址封存、洋封存、矿石碳化、工业利用、生态封存等,其中地质封存是主流方式。