Gas-phase, catalytic hydrodeoxygenation of propanoic acid, over supported group VIII noble metals: Metal and support effects

Theoretical investigation of the decarboxylation and decarbonylation mechanism of propanoic acid over a Ru(0 0 0 1) model surface

“…Step Our predictions from this microkinetic model agree well with experimental observations by Olcay et al [14] and Lugo-Jose et al [15]. Olcay et al studied the hydrodeoxygenation of acetic acid (CH 3 COOH) over Ru/C catalysts and found that at 458 K and low H 2 partial pressure, methane production has a selectivity of $70%, following a decarbonylation mechanism.…”

“…On the other hand, it has been shown that when flowing acetic acid over Ru/C at a low H 2 partial pressure (<1 bar) [14], mostly methane ($70% selectivity) and only small amounts of ethanol are produced ($6% selectivity). Experiments on propanoic acid on Ru/SiO 2 at low H 2 partial pressure (<1 bar) by Lugo-Jose et al [15] showed that the selectivity to C 2 hydrocarbons increases with increasing temperature in the range of 473-573 K and that the deoxygenation mechanism proceeds by decarbonylation.…”

“…To gain more insights into the DCN and DCX mechanisms of organic acids (such as propanoic acid) on transition metal surfaces and to possibly design novel metal catalysts, it is necessary to study multiple metal surfaces. Ruthenium is more oxophilic than palladium and has experimentally been found to be an active catalyst for the conversion of organic acids to hydrocarbon molecules [2,[13][14][15]. Experiments on the HDO of propanoic acid over Ru/C by Chen et al [13] and the HDO of acetic acid over Ru/C by Olcay et al [14] show that at high H 2 partial pressure (>20 bar) and at temperatures of around 400 K, Ru/C has a high selectivity to propanol and ethanol, respectively.…”

Hydrodeoxygenation of acetone–furfural condensation adducts over alumina-supported noble metal catalysts

“…Although, at first insight, the values of the activation energies seem lower than expected, similar values were recently reported for HDO.Activation energies of about 10 kJ/mol are obtained for the propanoic acid HDO using supported Pd catalysts [45]. Concerning to biomass model compounds (furans, aldehydes, etc.…”

Unraveling the mechanism of propanoic acid hydrodeoxygenation on palladium using deuterium kinetic isotope effects

“…For instance, early studies showed that supported palladium offers a strong activity and selectivity for the HDO of PAc [15][16][17][18][19]. _ENREF_13While kinetic studies reveal overall reaction rates, reaction orders, and apparent activation barriers, they do not provide enough information for determining the fundamental elementary steps involved in the reaction mechanism [20,21].…”