First-Principles Microkinetic Modeling of Methane Oxidation over Pd(100) and Pd(111)
Artikel i vetenskaplig tidskrift, 2016

The intrinsic activity of Pd(100) and Pd(111) for methane oxidation is investigated by Density Functional Theory (DFT)-based mean-field microkinetic modeling. The model includes 32 reaction steps, and the calculated turnover frequencies together with reaction orders compare favorably with experimental data. On both surfaces, the reaction proceeds via complete dehydrogenation of methane to elemental carbon followed by different mechanisms for carbon oxidization. Pd(100) is found to be more active than Pd(111) at temperatures from 400 to 1000 K. For both surfaces, the reaction order in methane approaches unity with increasing temperature. The reaction order in water is positive at low temperatures owing to water-promoted carbon oxidation. Methane dissociation is the main rate-controlling step for Pd(111), whereas formation of COH and CO is also controlling the rate over Pd(100). The present work uncovers the detailed reaction mechanisms for complete methane oxidation over palladium, which can be used in catalyst design to target the rate-controlling steps.

methane oxidation

heterogeneous catalysis

Pd(111)

Pd(100)

palladium

microkinetic modeling

DFT

Författare

Mikkel Jørgensen

Kompetenscentrum katalys (KCK)

Chalmers, Fysik, Kemisk fysik

Henrik Grönbeck

Kompetenscentrum katalys (KCK)

Chalmers, Fysik, Kemisk fysik

ACS Catalysis

2155-5435 (eISSN)

Vol. 6 10 6730-6738

Styrkeområden

Nanovetenskap och nanoteknik

Ämneskategorier

Fysikalisk kemi

Annan fysik

Teoretisk kemi

Den kondenserade materiens fysik

Infrastruktur

C3SE (Chalmers Centre for Computational Science and Engineering)

DOI

10.1021/acscatal.6b01752

Mer information

Skapat

2017-10-07