ON THE REACTION-MECHANISM FOR HYDROCARBON FORMATION FROM METHANOL OVER SAPO-34 .1. ISOTOPIC LABELING STUDIES OF THE CO-REACTION OF ETHENE AND METHANOL
ON THE REACTION-MECHANISM FOR HYDROCARBON FORMATION FROM METHANOL OVER SAPO-34 .1. ISOTOPIC LABELING STUDIES OF THE CO-REACTION OF ETHENE AND METHANOL
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DOI：
10.1006/jcat.1994.1312
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发表时间：
1994-10-01
影响因子：
7.3
通讯作者：
KOLBOE, S
中科院分区：
文献类型：
--
作者：
DAHL, IM;KOLBOE, S
C-13-甲醇和C-12乙烯(以乙醇形式进料)在400℃的流动体系中以Ar为载气(稀释剂)在SAPO-34上发生了共反应。进料中含有相同数量的C-13和C-12原子。产物用CC-MS进行分析，从而确定了反应器流出物的同位素组成。乙醇立即转化为乙烯，因此反应体系相当于由甲醇/乙烯/水组成的进料。当甲醇完全或几乎完全转化为碳氢化合物时，乙烯的大部分没有反应。产物中的丙烯和丁烯主要由甲醇生成，含有大量过剩的C-13原子。乙烯流出物主要由全部C-12或全部C-13原子组成，仅有少量C-12-C-13分子。反应体系从最初非常活跃的催化剂开始，直到催化剂充分失活，C-1没有完全转化为碳氢化合物。随着催化剂失活的进展，乙烯未反应生成以及所有新碳氢化合物从甲醇生成的趋势变得更加明显。结果表明，在该催化剂上，较高碳氢化合物不是由乙烯连续甲基化生成的。以前提出的“碳池”机制可以解释在产品和同位素分布中看到的总体影响。(C)1994年学术出版社。
C-13-Methanol and C-12 ethene (fed as ethanol) have been co-reacted over SAPO-34 in a flow system at 400 degrees C using argon as a carrier (diluent) gas. The feed contained an equal number of C-13 and C-12 atoms. The products were analyzed by CC-MS, allowing the determination of the isotopic composition of the reactor effluent. The ethanol was immediately converted to ethene, so the reaction system was equivalent to a feed consisting of methanol/ethene/water. While the methanol was completely or almost completely converted to hydrocarbons, the larger part of the ethene emerged unreacted. The products propene and butenes were mostly formed from methanol and contained a large excess of C-13 atoms. The ethene effluent consisted mainly of all C-12 or all C-13 atoms, and only to a small extent of C-12-C-13 molecules. The reaction system was followed from an initially very active catalyst until the catalyst was sufficiently deactivated that C-1 was not completely converted to hydrocarbons. The tendency for ethene to emerge unreacted, and for all new hydrocarbons to be formed from methanol became more pronounced with progressing catalyst deactivation. The results show clearly that the higher hydrocarbons are, over this catalyst, not formed by successive methylations of ethene. A previously proposed ''carbon pool'' mechanism can explain the gross effects seen in the product and isotopic distribution. (C) 1994 Academic Press, Inc.