Heterolytic and heterotopic dissociation of hydrogen on ceria-supported gold nanoparticles. Combined inelastic neutron scattering and FT-IR spectroscopic study on the nature and reactivity of surface hydrogen species

被引：87

作者：

Juarez, Raquel ^{[1
]}

Parker, Stewart F. ^{[2
]}

Concepcion, Patricia ^{[1
]}

Corma, Avelino ^{[1
]}

Garcia, Hermenegildo ^{[1
]}

机构：

[1] Univ Politecn Valencia, Inst Univ Tecnol Quim CSIC UPV, Valencia 46022, Spain

[2] STFC Rutherford Appleton Lab, ISIS Facil, Chilton OX11 0QX, Didcotoxon, England

来源：

CHEMICAL SCIENCE | 2010年 / 1卷 / 06期

关键词：

CHEMOSELECTIVE HYDROGENATION; AEROBIC OXIDATION; CARBON-DIOXIDE; CATALYSTS; H-2; PEROXIDE; AU/TIO2; OXYGEN; O-2; EPOXIDATION;

D O I：

10.1039/c0sc00336k

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

Inelastic neutron scattering of gold nanoparticles (3-4 nm, 0.48 wt%) supported on nanoparticulate ceria (5 nm) (Au/CeO2) shows that hydrogen treatment of Au/CeO2 gives rise to the appearance of a new band (400-600 cm(-1)) corresponding to bridging hydroxyl groups. This band disappears (without observing the appearance of any new band) when the sample is exposed to CO2 or O-2. FT-IR spectroscopy on the same samples shows the formation of Au-H after hydrogen chemisorption. The Au-H band also disappears when the sample is subsequently treated with CO2 or O-2. In the last case formation of hydroperoxide is observed. The band assignments were supported by isotopic labelling with D-2 and O-18(2). The above data clearly establish that upon treatment of Au/CeO2 with hydrogen at 150 degrees C, heterolytic bond cleavage of dihydrogen occurs leading to a proton bonded to a ceria oxygen and a hydride bonded to gold.

引用

页码：731 / 738

页数：8