碱改性γ－Al_2O_3催化剂表面碱强度分布与COS水解活性的研究  

Study on the Alkalized γ-Al_2O_3 Catalyst for its Base Strength Distribution and Catalytic Activity

作　　者：李春虎[1] 郭汉贤[1] 谈世韶[1] 

机构地区：[1]太原工业大学煤化工研究所,天津大学化工系工业催化室

出　　处：《分子催化》1994年第4期305-312,共8页Journal of Molecular Catalysis(China)

摘　　要：用非水滴定法和Ｈａｍｍｅｔｔ系列指示剂测定了ＣＯＳ水解碱改性γ－Ａｌ_２Ｏ_３催化剂的表面碱强度分布．发现表面碱强度分布不均匀与表面能量分布不均匀相呼应．采用零点酸碱强度（Ｈ_（０，ｍａｘ））及碱中心区域分析法，Ｂｒｏｎｓｔｅｄ催化定律，进一步证实ＣＯＳ水解反应具有明显碱催化特征，较高活性催化剂的Ｈ_（０，ｍａｘ）一般为１０左右，对ＣＯＳ水解反应起主要作用的碱性中心的碱强度（Ｈ_０）为４．８≤Ｈ_０≤９．８．对碱金属氧化物改性后的γ－Ａｌ_２Ｏ_３催化剂，Ｂｒｏｎｓｔｅｄ规律在每个碱强度分区域内是适用的．Using a series of Hammett indicators and non-aqueous titrimetry the base strength distribution of alkalized γ-Al_2O_3 catalysts for COS hydrolysis was determined.It was observed that the non-uniform distribution of base strength over catalyst surface corresponds to energetically heterogeneous catalyst surface.The zero acid-base strength(H0,max),the regional analytieal method and Bronsted relation were introduced to show that the reaction of COS hydrolysis exhibits pronounced base catalytic character.The values of H0,max responsible for peak activites are approximately 10.The base strength related to the greatest contribution of COS hydrolysis is in the range of 4.8≤H_0≤9.8.For catalysts modified by alkali metal oxide Bronsted relation can be employed to correlate quantitatively the rate constant with the basic strength for each region.

关 键 词：氧化铝 碱改性 羰基硫 碱强度分布 催化剂 

分 类 号：TQ426.81[化学工程]