Formation of Ammonia during the NO-H2 Reaction over Pt/ZrO2

被引：15

作者：

Nanba, T. ^{[1
]}

Meunier, F. C. ^{[2
]}

Hardacre, C. ^{[2
]}

Breen, J. P. ^{[2
]}

Burch, R. ^{[2
]}

Masukawa, S. ^{[1
]}

Uchisawa, J. ^{[1
]}

Obuchi, A. ^{[1
]}

机构：

[1] Natl Inst Adv Ind Sci & Technol, Res Ctr New Fuels & Vehicle Technol, Tsukuba, Ibaraki 3058569, Japan

[2] Queens Univ Belfast, Sch Chem, Ctr Theory & Applicat Catalysis, Belfast BT9 5AG, Antrim, North Ireland

来源：

JOURNAL OF PHYSICAL CHEMISTRY C | 2008年 / 112卷 / 46期

基金：

日本学术振兴会;

关键词：

D O I：

10.1021/jp8060812

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：

The mechanism for the formation of NH3 during the NO-H-2 reaction over Pt/ZrO2 was studied. Steady-state isotopic transient kinetic analysis was carried out with isotopic switching from (NO)-N-15-D-2 to (NO)-N-14-D-2, and the results revealed that formation of N-2 and N2O was associated with linearly adsorbed NO on the Pt surface, whereas ammonia formation was associated with NDx species adsorbed on ZrO2. The adsorbed NHx species were not observed on the surface of ZrO2 during NH3 adsorption. From transient kinetic experiments, the formation rates of NHx species and of gaseous NH3 agreed with each other, suggesting that the NHx species on ZrO2 was an ammonia intermediate. The NDx species did not react with D-2 directly, but H-D exchange occurred easily. The addition of H2O to the NO-H-2 feed gas enhanced the formation of NH3. In situ diffuse reflectance spectra and transient kinetic analysis revealed that H2O enhanced the conversion of NHx species to NH3.

引用

页码：18157 / 18163

页数：7