Kinetics-assisted discrimination of active sites in Ru catalyzed hydrolytic dehydrogenation of ammonia borane
Kinetics-assisted discrimination of active sites in Ru catalyzed hydrolytic dehydrogenation of ammonia borane
复制标题
动力学辅助辨别钌催化氨硼烷水解脱氢活性位点
DOI：
10.1039/c8re00223a
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发表时间：
2019-02-01
影响因子：
3.9
通讯作者：
Duan, Xuezhi
中科院分区：
文献类型：
--
作者：
Fu, Wenzhao;Chen, Wenyao;Duan, Xuezhi
从多相催化反应中催化剂活性位点的角度识别结构敏感性的根本性质具有重要的科学和工业重要性。在这项工作中，通过结合多方面的动力学分析和模型计算，探索了尺寸敏感的Ru催化氨硼烷水解脱氢中活性位点的动力学辅助识别。发现所采用的不同尺寸的Ru/CNT催化剂以hcp晶体结构和截头六角双锥体的形式存在。尺寸不敏感的活化能表明，一种类型的 Ru 活性位点主要主导反应，被识别为 Ru 边缘原子。动力学同位素分析与 DFT 计算的进一步结合表明，在此类活性位点上有利于发生速率决定步骤。这里揭示的见解不仅可以为如何实现结构敏感反应活性位点的动力学辅助识别提供新的思路，而且可以指导反应中Ru催化剂的合理设计和优化。
Identifying the underlying nature of the structure sensitivity from the catalyst active site point of view in heterogeneous catalytic reactions is of prime scientific and industrial importance. In this work, the kinetics-assisted discrimination of active sites is explored in size-sensitive Ru catalyzed hydrolytic dehydrogenation of ammonia borane by combining multi-faceted kinetics analysis with model calculations. The differently sized Ru/CNT catalysts employed are found to exist in the form of a hcp crystal structure and a truncated hexagonal bipyramid. The size-insensitive activation energies indicate that one type of Ru active site mainly dominates the reaction, which is discriminated as the Ru edge atom. Further combination of kinetic isotopic analysis with DFT calculations suggests the favorable occurrence of the rate-determining step on such active sites. The insights revealed here could shed new light not only on how to achieve the kinetics-assisted discrimination of active sites for structure-sensitive reactions, but also on guiding the rational design and optimization of Ru catalysts for the reaction.