Catalytic hydrogenation of CO₂ to methane over supported Pd, Rh and Ni catalysts

Abstract

CO2 methanation over Rh/Al2O3, Rh/CeO2 and Ni/CeO2 at 350 °C highlighting the different surface speciation during reaction.

Structure–function relationship during CO2 methanation over Rh/Al2O3 and Rh/SiO2 catalysts under atmospheric pressure conditions

“…However, there are no contributions observed from a Rh-O-Al shell which shall appear at a distance above 2.5 Å (R ∼ 2. The activity of the catalysts measured by mass spectrometry showed results comparable to the ones reported on our previous publication 11 and summarized in Table 1 and, for simplicity, we focus here on the structural changes of the Rh and support phases occurring during the CO 2 methanation reaction.…”

“…A detailed DRIFTS study of CO 2 hydrogenation over Rh/Al 2 O 3 under transient operation conditions has been presented in our previous publication 11 and, therefore, here we focus our attention on the different surface species formed during the reaction and how these differ depending on the choice of the support.…”

“…12,13 Recently, we have studied different systems consisting of metals (Pd, Rh and Ni) supported on both reducible (CeO 2 ) and nonreducible (Al 2 O 3 and SiO 2 ) oxides for the activation of CO 2 and its reaction with H 2 under atmospheric pressure conditions and at relatively low temperatures (250-350°C). 11 Interestingly, the results showed that Rh supported on both alumina and ceria exhibits high activity in the hydrogenation of CO 2 for methane production and the catalysts supported on SiO 2 have negligible activity. Therefore, a clear distinction between the reactivity of catalysts supported on reducible vs. nonreducible oxides could not be made based on the kinetic data.…”

“…This indicates an increased number of neighboring atoms, in line with our recent XRD results for the as-prepared catalyst which suggested larger particles of Rh oxide for the silica supported sample. 11 To gain more information about the local structure surrounding the Rh atoms, a qualitative EXAFS analysis was performed. The associated Fourier transforms are shown on the right panels in Fig.…”

Formates for green catalytic reductions via CO2 hydrogenation, mediated by magnetically recoverable catalysts

“…Furthermore, direct catalytic hydrogenation may have selectivity problems especially in the presence of the highly active heterogeneous precious metal catalysts [7,8]. It is well known, that CO 2 can be catalytically reduced by H 2 to various products such as hydrocarbons, carboxylic acids, aldehydes and alcohols by homogeneous or heterogeneous way [9][10][11][12].…”