| Cu/AC催化剂在气相氧化羰基化反应中铜状态变化分析 |
| Copper States in Cu/AC Catalyst during Gas-Phase Oxidative Carbonylation of Methanol to Dimethyl Carbonate |
| 作者 | 单位 | E-mail | | 郑华艳 | 太原理工大学, 煤科学与技术教育部和山西省重点实验室, 太原 030024 | | | 秦瑶 | 太原理工大学, 煤科学与技术教育部和山西省重点实验室, 太原 030024 | | | 李忠 | 太原理工大学, 煤科学与技术教育部和山西省重点实验室, 太原 030024 | lizhong@tyut.edu.cn | | 张国强 | 太原理工大学, 煤科学与技术教育部和山西省重点实验室, 太原 030024 | | | 孟凡会 | 太原理工大学, 煤科学与技术教育部和山西省重点实验室, 太原 030024 | |
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| 摘要: 采用活性炭（AC）载体浸渍醋酸铜后热分解制得Cu/AC催化剂，用于催化甲醇直接气相氧化羰基化合成碳酸二甲酯，通过对反应不同时间的催化剂进行XRD、TEM、H2-TPR、AAS、XPS和O2-TPD等表征，探讨反应过程中铜物种状态的变化规律及其催化性能。结果表明，新鲜催化剂中铜物种以单质Cu形式存在；进行反应后，单质Cu吸附反应气氛中的O2并转化为晶格氧生成Cu2O物种，反应4h时，催化剂表面主要为分散均匀、粒径较小的Cu2O，为反应的进行提供活性组分和晶格氧，表现出较好的催化活性；随着反应继续进行，催化剂中Cu2O晶粒长大，并被表面吸附氧进一步氧化为CuO，Cu2O含量减少，CuO含量增加，同时铜物种发生了较严重的团聚现象，导致催化剂活性下降。 |
| 关键词: 铜基催化剂 无氯 铜状态 氧化羰基化 气相法 碳酸二甲酯 |
| 基金项目: 国家自然科学基金（No.21106092，21276169）和山西省科技攻关项目（No.20120321003-03）资助。 |
| Abstract: The chloride-free copper-based activated carbon (Cu/AC) catalyst was prepared via pyrolysis of copper acetate supported on activated carbon (Cu(CH3COO)2/AC) by the incipient wetness impregnation method and used to catalyze vapor-phase oxycarbonylation of methanol to dimethyl carbonate (DMC). The chemical composition and morphology of the catalysts with different reaction times were characterized by means of XRD, TEM, H2-TPR, AAS, XPS and O2-TPD. The results show that the main copper species in fresh Cu/AC catalyst is Cu, which is easily oxidized to Cu2O during reaction process. After reaction for 4 h in the gas phase reaction system, the main active species Cu2O is well dispersed on the surface of AC, providing Cu(Ⅰ) and lattice oxygen for oxycarbonylation of methanol. With the growing up of crystalline grain size of Cu2O species, Cu2O is further oxidized to CuO. Subsequently, the amount of Cu2O species is decreased, leading to the decreasing of catalytic activity. Meanwhile, the deactivation rate of the catalyst is accelerated by the aggregation of copper species during the reaction process. |
| Keywords: copper based catalyst chloride-free copper states oxidative carbonylation gas-phase dimethyl carbonate |
| 投稿时间：2014-03-22 修订日期：2014-04-28 |
| 摘要点击次数: 2409 |
| 全文下载次数: 2073 |
| 郑华艳,秦瑶,李忠,张国强,孟凡会.Cu/AC催化剂在气相氧化羰基化反应中铜状态变化分析[J].无机化学学报,2014,30(9):2111-2118. |
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