Preparation and regeneration of supported single-Ir-site catalysts by nanoparticle dispersion via CO and nascent I radicals

被引：14

作者：

Feng, Siquan ^{[1
,6
]}

Hemberger, Patrick ^{[2
]}

Bodi, Andras ^{[2
]}

Song, Xiangen ^{[1
]}

Yu, Tongpo ^{[3
]}

Jiang, Zheng ^{[4
]}

Liu, Yang ^{[4
]}

Ding, Yunjie ^{[1
,5
]}

机构：

[1] Chinese Acad Sci, Dalian Inst Chem Phys, Dalian Natl Lab Clean Energy, Dalian 116023, Peoples R China

[2] Paul Scherrer Inst, Lab Synchrotron Radiat & Fetntochem, CH-5232 Villigen, Switzerland

[3] Univ Sci & Technol China, Dept Chem Phys, Hefei 230026, Peoples R China

[4] Chinese Acad Sci, Shanghai Inst Appl Phys, Shanghai Synchrotron Radiat Facil, Shanghai 201204, Peoples R China

[5] Chinese Acad Sci, Dalian Inst Chem Phys, State Key Lab Catalysis, Dalian 116023, Peoples R China

[6] Univ Chinese Acad Sci, Beijing 100049, Peoples R China

来源：

JOURNAL OF CATALYSIS | 2020年 / 382卷

基金：

瑞士国家科学基金会; 国家重点研发计划;

关键词：

Heterogeneous single-Ir-site catalysts; Preparation and regeneration; Nanoparticle dispersion; In situ PEPICO spectrum; Radicals detection; SURFACE ORGANOMETALLIC CHEMISTRY; METHANOL CARBONYLATION; HETEROGENEOUS CATALYSIS; FAST PYROLYSIS; IRIDIUM; CHEMISORPTION; REDISPERSION; PARTICLES; MECHANISM; CLUSTERS;

D O I：

10.1016/j.jcat.2019.12.040

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

Heterogeneous single-metal-site catalysts (HSMSCs) have been attracting increasing interest because of their unique traits. However, deactivation induced by metal agglomeration restrains the application especially when they have high metal loading. Herein, we present a method of CO/CH3I thermal treatment to prepare and regenerate Ir HSMSCs on activated carbon (AC) via atomically dispersive strategy of nanoparticles (NPs). The intermediate key species during this process, radicals, have been detected in situ by photoelectron photoion coincidence spectroscopy with vacuum ultraviolet synchrotron radiation (PEPICO-VUV). Our findings imply a strong relationship between I radicals' as well as CO molecule's roles in the breakage of NPs metal-metal bond. NPs with size larger than about 5 nm are difficult to be dispersed due to strong Ir-Ir bond together with the kinetic stability. Besides, 5 wt% Ir HSMSCs deactivated by metal agglomeration can be regenerated repeatedly and regain their initial activity for heterogeneous methanol carbonylation. (C) 2020 Elsevier Inc. All rights reserved.

引用

页码：347 / 357

页数：11