摘要
以ＸＲＤ，ＥＸＡＦＳ和ＥＳＲ等手段考察了ＣｕＯ／ＺｒＯ２催化剂及其还原态的结构．结果表明，在ＣｕＯ／ＺｒＯ２中铜以ＣｕＯ的形式存在，ＺｒＯ２载体对所负载的ＣｕＯ的结构有影响．ＣｕＯ的分散度与焙烧温度有关，在适当的温度下焙烧，负载于ＺｒＯ２上的ＣｕＯ可自发分散．在还原态试样中铜主要以金属铜的形式存在；但是当试样中铜的含量小、铜的分散度高时有铜的氧化物存在，其Ｃｕ－Ｏ键距介于ＣｕＯ和Ｃｕ２Ｏ之间．ＣｕＯ／ＺｒＯ２中ＣｕＯ的晶粒小则对应的还原态试样中铜的晶粒也小．单位质量铜上的甲醇产率随铜分散度的提高而增大．
The structure of CuO/ZrO 2 catalysts and their reduced states has been characterized by means of XRD, EXAFS and ESR. It is found that CuO is the only compound containing copper in CuO/ZrO 2 and the ZrO 2 support has influence on the structure of CuO. CuO in CuO/ZrO 2 can disperse spontaneously at a proper calcination temperature. In the reduced catalyst samples, only metal copper is detected when the weight percent of CuO in CuO/ZrO 2 exceeds 12%; when the CuO content is 3 5%, metal copper is predominant but not exclusive, copper oxide also exists, in which the bond distance of Cu-O is between that of pure CuO and pure Cu 2O. With the decrease of the content of CuO in CuO/ZrO 2, the dispersion of CuO (for the CuO/ZrO 2) and metal copper (for the reduced samples) on ZrO 2 increases and the productivity of methanol from CO/2H 2 on per gram copper also increases.
出处
《催化学报》
SCIE
CAS
CSCD
北大核心
1996年第3期222-226,共5页
关键词
氧化铜
氧化锆
合成气
甲醇
催化剂
XRD
ESR
Copper oxide, Zirconia, X ray diffraction, Extended X ray absorption fine structure, Synthetic gas, Methanol
