CAJ | 학술논문

采用表面活性剂改性的沉淀法合成了系列掺杂钇、镧、钡的氧化锆铝复合氧化物.通过XRD、XRF、低温N_2吸附和CO脉冲化学吸附等手段考察了表面活性剂、助剂、焙烧温度对复合材料结构、孔结构以及负载0.5%铑催化剂的分散性能等的影响.研究表明:与采用常规沉淀法合成的氧化锆铝复合氧化物相比,添加表面活性剂合成的样品具有更大的比表面积、孔容和适合的孔径分布.分别或同时掺杂La、Ba、Y合成的氧化锫铝复合氧化物都能抑制氧化铝的α相变,提高复合材料和催化剂表面金属Rh的高温抗烧结能力,特别是同时掺杂La、Ba、Y合成的Rh/LBYZA样品经1 100℃4 h焙烧后仍有17.82%的金属分散度.以LBYZA为载体制备的新鲜催化剂(600℃4 h焙烧样品)在CO选择还原NO反应中NO和CO的起燃温度分别为240、243℃,完全燃烧温度分别为273、280℃,表现出较高的催化活性.
채용표면활성제개성적침정법합성료계렬참잡을、란、패적양화고려복합양화물.통과XRD、XRF、저온N_2흡부화CO맥충화학흡부등수단고찰료표면활성제、조제、배소온도대복합재료결구、공결구이급부재0.5%로최화제적분산성능등적영향.연구표명:여채용상규침정법합성적양화고려복합양화물상비,첨가표면활성제합성적양품구유경대적비표면적、공용화괄합적공경분포.분별혹동시참잡La、Ba、Y합성적양화부려복합양화물도능억제양화려적α상변,제고복합재료화최화제표면금속Rh적고온항소결능력,특별시동시참잡La、Ba、Y합성적Rh/LBYZA양품경1 100℃4 h배소후잉유17.82%적금속분산도.이LBYZA위재체제비적신선최화제(600℃4 h배소양품)재CO선택환원NO반응중NO화CO적기연온도분별위240、243℃,완전연소온도분별위273、280℃,표현출교고적최화활성.
A series of ZrO_2 -Al_2O_3 mixed oxides with La,Ba and Y were prepared by co-precipitation method which modified by surfactant.The samples were characterized by XRD,XRF,BET measurements and CO pulse chemiadsorption.The effect of surfactant,promoter and calcination temperature on structure,pore structure of these materials and dispersion of Rh on composite supports was investigated.It was found that compared with materials prepared by conventional co-precipitation method,the samples prepared by new method had larger specific surface area and pore volume,appropriate pore size distribution.No matter how adding La,Ba and Y separately or together,phase change of γ-Al_2O_3 to α-Al_2O_3 of the samples was inhibited and thermal stability of the composite supports and Rh was improved at high temperature.In particular,high dispersion of precious metals (D% =17.82%) of the catalyst Rh/LBYZA which adding La,Ba and Y together was achieved after calcination at 1 100℃ for 4 h.The catalyst supported on LBYZA after calcination at 600℃ for 4 h had higher catalytic activity for NO selective reduced by CO.Light-off temperature (T_(50%NO)=240,T_(50%CO)=243) and Combustion temperature (T_(90%NO)=273,T_(92%CO)=280) of NO and CO were lower than the catalysts supported on γ-Al_2O_3 and other ZrO_2-Al_2_3 materials.