CAJ | 학술논문

采用共沉淀法制备了LaF3-Cr2O3催化剂，并考察了催化剂对气相氟化四氯乙烯（PCE）反应性能的影响。结果表明，随着 La 掺杂量的增加，LaF3-Cr2O3催化剂上 PCE 的转化率不断升高，而有效产物（HCFC-123+HCFC-124+HFC-125）总选择性出现先升高后下降。当La掺杂为1%时，1LaF3-Cr2O3催化剂的气相氟化四氯乙烯（PCE）反应性能最佳，PCE的转化率和有效产物总选择性分别达到92.8%和90.1%。NH3程序升温脱附结果表明，随着La掺杂量的增加，LaF3-Cr2O3催化剂弱酸中心减少，催化剂酸强度和强酸中心数目增加。这是由于催化剂中LaF3和CrF3含量的增加所致，催化剂表面相对酸量的增加不利于有效产物（HCFC-123+HCFC-124+HFC-125）的生成。
채용공침정법제비료LaF3-Cr2O3최화제，병고찰료최화제대기상불화사록을희（PCE）반응성능적영향。결과표명，수착 La 참잡량적증가，LaF3-Cr2O3최화제상 PCE 적전화솔불단승고，이유효산물（HCFC-123+HCFC-124+HFC-125）총선택성출현선승고후하강。당La참잡위1%시，1LaF3-Cr2O3최화제적기상불화사록을희（PCE）반응성능최가，PCE적전화솔화유효산물총선택성분별체도92.8%화90.1%。NH3정서승온탈부결과표명，수착La참잡량적증가，LaF3-Cr2O3최화제약산중심감소，최화제산강도화강산중심수목증가。저시유우최화제중LaF3화CrF3함량적증가소치，최화제표면상대산량적증가불리우유효산물（HCFC-123+HCFC-124+HFC-125）적생성。
LaF3-Cr2O3 catalysts were prepared by a precipitation method,and their effects on the catalytic performance in vapor phase hydrofluorination of tetrachloroethylene were studied. With increasing La content,the tetrachloroethylene conversion over LaF3-Cr2O3 catalyst increases,while the total selectivity to effective products (HCFC-123 + HCFC-124 + HFC-125) first increases and then decreases. When the addition content of La is 1%,1LaF3-Cr2O3 catalyst exhibits the highest catalytic performance;the tetrachloroethylene conversion and the selectivity to effective products reach 92.8%and 90.1%,respectively. Results of NH3 temperature-programmed desorption indicate that the amount of weak acid sites of LaF3-Cr2O3 catalysts decreases with the increase of La content,while both the acid intensity and the amount of strong acid sites increase. It may be attributed to the increase in the content of LaF3 and amorphous CrF3 in the catalyst. Therefore,it could be concluded that the increase in the relative acid amount on the catalyst surface is unfavourable for the formation of effective products (HCFC-123+HCFC-124+HFC-125).