Relating Rates of Catalyst Sintering to the Disappearance of Individual Nanoparticles during Ostwald Ripening

被引：262

作者：

Challa, Sivakumar R. ^{[1
]}

Delariva, Andrew T. ^{[1
,2
]}

Hansen, Thomas W. ^{[1
,2
,3
]}

Helveg, Stig ^{[2
]}

Sehested, Jens ^{[2
]}

Hansen, Poul L. ^{[2
]}

Garzon, Fernando ^{[4
]}

Datye, Abhaya K. ^{[1
]}

机构：

[1] Univ New Mexico, Albuquerque, NM 87131 USA

[2] Haldor Topsoe Res Labs, DK-2800 Lyngby, Denmark

[3] Tech Univ Denmark, Ctr Electron Nanoscopy, DK-2800 Lyngby, Denmark

[4] Los Alamos Natl Lab, Los Alamos, NM 87545 USA

来源：

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY | 2011年 / 133卷 / 51期

关键词：

SUPPORTED METAL-CATALYSTS; STEAM-REFORMING CATALYSTS; SIZE DISTRIBUTIONS; MECHANISM; SILVER; DEGRADATION; ADSORPTION; DIFFUSION; PARTICLES; SURFACES;

D O I：

10.1021/ja208324n

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

Sintering of nanoparticles (NPs) of Ni supported on MgAl2O4 was monitored in situ using transmission electron microscopy (TEM) during exposure to an equimolar mixture of H-2 and H2O at a pressure of 3.6 mbar at 750 degrees C, conditions relevant to methane steam reforming. The TEM images revealed an increase in the mean particle size due to disappearance of smaller, immobile NPs and the resultant growth of the larger NPs. A new approach for predicting the long-term sintering of NPs is presented wherein microscopic observations of the ripening of individual NPs (over a span of a few seconds) are used to extract energetic parameters that allow a description of the collective behavior of the entire population of NPs (over several tens of minutes).

引用

页码：20672 / 20675

页数：4

共 35 条

[1] DIRECT OBSERVATION OF PARTICLE MOBILITY ON A SURFACE IN A GASEOUS ENVIRONMENT [J].