In situ DRIFTS study of CO coupling to dimethyl oxalate over structured Al-fiber@ns-AlOOH@Pd catalyst
In situ DRIFTS study of CO coupling to dimethyl oxalate over structured Al-fiber@ns-AlOOH@Pd catalyst
复制标题
结构Al-纤维@ns-AlOOH@Pd催化剂上CO与草酸二甲酯偶联的原位漂移研究
DOI：
10.1016/j.jcat.2016.09.031
复制
发表时间：
2016-12
影响因子：
7.3
通讯作者：
Yong Lu
中科院分区：
文献类型：
--
作者：
Chunzheng Wang;Pengjing Chen;Yakun Li;Guofeng Zhao;Ye Liu;Yong Lu
pd催化CO偶联制草酸二甲酯（DMO）工艺已经商业化，但其反应机理在COOCH3∗和COOCH3∗（∗，一个表面位点）之间仍有争议。在原位漫反射红外傅里叶变换光谱（DRIFTS）研究中，对一种高性能Al-fiber@ns-AlOOH@Pd催化剂进行了澄清这一争议。确实捕获了由c双键do和c单键do的拉伸振动和ch3的摇摆振动组成的中间物质，它们可以归属于COCOOCH3∗或COOCH3∗。为了区分COCOOCH3∗和COOCH3∗，采用草酰氯甲酯（CH3OCOCOCl）和氯甲酸甲酯（CH3OCOCl）在催化剂表面形成COCOOCH3∗和COOCH3∗，用于DRIFTS分析。有趣的是，在实际反应中观察到的中间物质的特征谱带与通过解离吸附CH3OCOCOCl得到的COCOOCH3 *物质相匹配。因此，证实了CO与DMO偶联的双羰基化反应途径，即连续插入两个CO分子到OCH3 *中形成COCOOCH3 *，然后结合OCH3 *生成DMO （CH3OCOCOOCH3）。
Pd-catalyzed CO coupling to dimethyl oxalate (DMO) process has been commercialized but its reaction mechanism is still open for debate between COCOOCH3∗and COOCH3∗(∗, a surface site).In situdiffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) studies were performed to clarify such controversy on a high-performance Al-fiber@ns-AlOOH@Pd catalyst. Intermediate species consisting of stretching vibrations of Cdouble bondO and Csingle bondO, and rocking vibration of CH3was indeed captured, which could be assigned to either COCOOCH3∗or COOCH3∗. To make discrimination between COCOOCH3∗and COOCH3∗, methyl oxalyl chloride (CH3OCOCOCl) and methyl chloroformate (CH3OCOCl) were employed to form COCOOCH3∗and COOCH3∗species on the catalyst surface for DRIFTS analyses. Interestingly, the characteristic bands of the as-observed intermediate species in the real reaction matched the obtained COCOOCH3∗species from dissociative adsorption of CH3OCOCOCl. A double carbonylation reaction pathway was thus confirmed for the CO coupling to DMO, i.e., consecutive insertion of two CO molecules into OCH3∗to form COCOOCH3∗followed by combining OCH3∗to yield DMO (CH3OCOCOOCH3).
登录
查看更多内容
Pd/ZnO 催化剂 CO 氧化偶联生成草酸二甲酯的稳定性增强：Mg2 掺杂的影响
影响因子：
12.9
作者：
Peng, Si-Yan;Xu, Zhong-Ning;Guo, Guo-Cong
通讯作者：
Guo, Guo-Cong
影响因子：
2.3
作者：
Shinichiro Uchiumi;K. Ataka;T. Matsuzaki
通讯作者：
Shinichiro Uchiumi;K. Ataka;T. Matsuzaki
影响因子：
3.8
作者：
Y. Tobón;H. Loreto;C. Védova;R. Romano
通讯作者：
Y. Tobón;H. Loreto;C. Védova;R. Romano
影响因子：
12.9
作者：
Yifeng Zhu;Xiao Kong;Dong-bo Cao;J. Cui;Yulei Zhu;Yong-wang Li
通讯作者：
Yifeng Zhu;Xiao Kong;Dong-bo Cao;J. Cui;Yulei Zhu;Yong-wang Li
影响因子：
--
作者：
Gao Zhenghong;Liu Zhong-chen;H. Fei;Xu Genhui
通讯作者：
Gao Zhenghong;Liu Zhong-chen;H. Fei;Xu Genhui