摘要
用共沉淀法制备了Ｃｕ－Ｆｅ系催化剂，它是由脂肪酸甲酯加氢制备高碳醇的新催化体系．催化剂经焙烧后的物相为ＣｕＯ，γ－Ｆｅ２Ｏ３和ＭｇＯ，形成了活性相的结构前驱．在反应条件下，ＣｕＯ首先被还原为金属态的Ｃｕ０，然后γ－Ｆｅ２Ｏ３被还原为Ｆｅ３Ｏ４；Ｃｕ０和Ｆｅ３Ｏ４共同参与催化该反应．本文用ＸＲＤ，ＴＧ－ＤＴＡ和Ｍｏｓｓｂａｕｅｒ谱等手段，结合催化剂的活性测定，确定了催化剂的活性相为Ｃｕ０和Ｆｅ３Ｏ４；ＭｇＯ可改变催化剂的电子结构和几何构型。
Cu Fe catalyst has higher activity for higher alcohol preparation from fatty methyl esters than Cu Cr catalyst and has no poison and pollution. The catalyst can be prepared by coprecipitation with Cu(NO 3) 2, Fe(NO 3) 3, Mg metal powder and NaOH. In order to obtain γ Fe 2O 3 , Fe 3+ in Fe(NO 3) 3 should be reduced to Fe 2+ before coprecipitation. The optimal composition of the catalyst is CuO 56%, γ Fe 2O 3 35% and MgO 9%. The active phases of the catalyst have been studied by XRD, TG DTA, M[AKo¨D5]ssbauer spectra and activity determination. It has been confirmed that the phases of the catalyst are CuO, γ Fe 2O 3 and MgO after calcination. These oxides form structure precursors of the active phases. Under reaction conditions ( t =285℃, p H 2 =10 MPa), CuO is first reduced to Cu 0 and then γ Fe 2O 3 is reduced to Fe 3O 4. It also can be observed by activity determination that the increase of activity is simultaneous with the formation of Cu 0 and Fe 3O 4 phases, and it is Cu 0 and Fe 3O 4 that catalyze the reaction, so the Cu 0 and Fe 3O 4 phases are the active phases. MgO can change the electronic and geometric structure of the catalyst and play a promotive part in the reaction.
出处
《催化学报》
SCIE
EI
CAS
CSCD
北大核心
1996年第6期497-501,共5页
