Adsorption and Decomposition of Formic Acid on Cobalt(0001)

Abstract

Formic acid can undergo dehydration or dehydrogenation with variable selectivity over a range of metal catalysts. The selectivity among these reactions depends on the reaction mechanism and reaction conditions pertinent on each surface. This work provides mechanistic insight on the decomposition of formic acid on cobalt at high and low temperature regimes. The adsorption and decomposition of formic acid on a Co(0001) single crystal was studied in ultra-high vacuum by X-ray photoelectron spectroscopy (XPS) and temperature programmed desorption (TPD). Insight is provided using DFT calculations. In the low temperature regime, formic acid adsorbs molecularly on the surface at 130 K. Partial decomposition produces CO at 140 K, and at 160 K the decomposition of formic acid into formate, which is a thermodynamic sink, is dominant. Water can be formed at low temperature via bimolecular processes. At high temperature (>400 K) the similar barriers for decomposition of the formate species lead to the concomitant production of CO, CO2 and H2. The correlation between experiment and theory provides a framework for the interpretation of surface species and reaction path operating in different regimes.

Significance of the Mn-Oxidation State in Catalytic and Noncatalytic Promotional Effects of MnOx Domains in Formic Acid Dehydrogenation on Pd/MnOx Interfaces

“…FA decomposition on various late transition-metal surfaces such as Pd, 8−12 Rh, 13−15 Ru, 16,17 Pt, 18−20 Cu, 21−23 Co, 24 Ag, 25 as well as Pd−Ag 26 and Pd−Au 27 bimetallic systems, has been extensively studied under ultrahigh vacuum (UHV) conditions. These studies showed that many high-coordination transition-metal single-crystal surfaces were capable of carrying out FA dehydrogenation effectively.…”

Enhancement of Formic Acid Dehydrogenation Selectivity of Pd(111) Single Crystal Model Catalyst Surface via Brønsted Bases

“…FA decomposition on several group-VIII transition-metal surfaces such as Pd, 12−16 Rh, 17−19 Ru, 20,21 Pt, 22−24 Cu, 25−27 Co, 28 Ag, 29 and their bimetallic combinations 30 has been extensively studied under ultrahigh vacuum (UHV) conditions.…”

Effect of coverage on the magnetic properties of –COOH, –SH, and –NH2 ligand-protected cobalt nanoparticles

“…102 In accord with the most favourable binding modes suggested by experimental studies and DFT/metadynamics calculations, initial forms of interaction of acetic acid, ethanamine, and ethanethiol molecules were bridging bidentate, bridging monodentate, and three-fold monodentate, respectively. 44,[95][96][97][98] No changes in the interaction modes were observed upon the structural optimisation. Density of the passivating coating was determined as the number of Co atoms interacting with adsorbed molecules over the total number of surface Co atoms, where full coverage is reached once every surface Co atom interacts with one ligand molecule through a single bond.…”