Mechanistic and microkinetic analysis of CO2 hydrogenation on ceria.

Phys Chem Chem Phys

Department of Energy, Environmental and Chemical Engineering, Washington University, St. Louis, Missouri, USA.

Published: March 2016

We use density functional theory (DFT) calculations to investigate the mechanism of CO2 hydrogenation to methanol on a reduced ceria (110) catalyst, which has previously been shown to activate CO2. Two reaction channels to methanol are identified: (1) COOH pathway via a carboxyl intermediate and (2) HCOO pathway via a formate intermediate. While formaldehyde (H2CO) appears to be the key intermediate for methanol synthesis, other intermediates, including carbine diol, formic acid and methanol, are not feasible due to their high formation energies. Furthermore, direct formyl hydrogenation to formaldehyde is not feasible due to its high activation barrier. Instead, we find that conversion of H-formalin (H2COOH*) to formaldehyde is kinetically more favorable. The formaldehyde is then converted to methoxy (H3CO*), and finally hydrogenated to form methanol. Microkinetic analyses reveal the rate-limiting steps in the reaction network and establish that the HCOO route is the dominant pathway for methanol formation on this catalyst.

Download full-text PDF

Source
http://dx.doi.org/10.1039/c5cp07469jDOI Listing

Publication Analysis

Top Keywords

co2 hydrogenation
8
feasible high
8
methanol
6
mechanistic microkinetic
4
microkinetic analysis
4
analysis co2
4
hydrogenation ceria
4
ceria density
4
density functional
4
functional theory
4

Similar Publications

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!