Reverse water–gas shift reaction catalyzed by diatomic rhodium anions

Abstract

The reverse water-gas shift (RWGS, CO2 + H2  CO + H2O, ∆H298 = +0.44 eV) reaction mediated by the diatomic anion Rh2 was successfully constructed. The generation of gas-phase...

High activity in the dry reforming of methane using a thermally switchable double perovskite and in situ generated molecular level nanocomposite

“…Sustained DRM activity also points to the involvement of methanation and reverse water gas-shift reaction (RWGS) reactions that may not be completely ruled out. 23 In summary, a molecular level nanocomposite constituted by the oxides corresponding to La 2 NiMnO 6 composition together with a certain portion of metallic Ni is the actual performer, and there occurs reversible thermal switching between this nanocomposite and the parent double perovskite, making it a novel catalyst for the dry reforming of methane.…”

Filtration of the preferred catalyst for reverse water-gas shift among Rhn−(n= 3–11) clusters by mass spectrometry under variable temperatures

“…15 Herein, benefiting from a state-of-the-art high-temperature ion trap reactor, we demonstrated that the Rh 4 − cluster strikingly sur- towards the direction of the RWGS was primarily placed on weakening CO bonding after O-CO scission in order to facilitate CO desorption [47][48][49][50] because H 2 oxidation is relatively facile to proceed. 6,27 Fig. 5c shows that although the absolute binding energy of CO on products Rh n CO 2 − generally decreases with an increase in cluster size, the temperature required to release CO becomes higher for reactions Rh n − (n = 5-9) + CO 2 (T > 500 K) with respect to that for the reaction Rh 4 − + CO 2 (T ≥ 443 K).…”

“…However, available reactions are restricted to elementary steps and the catalysis of CO 2 hydrogenation has been scarcely established. 27,28 The endothermic nature of CO 2 hydrogenation requires external energies, while related conversions mediated with gas-phase species under high temperatures have rarely been reported. 29 Herein, by employing a homemade time-of-flight mass spectrometer (TOF-MS) coupled with a newly-developed high-temperature ion trap reactor that can trap ions to react with reactants at a temperature up to 873 K, 30 the catalysis of the RWGS mediated with the Rh n − ( n = 3–11) clusters was identified under variable temperatures (298–783 K) and the critical temperature that each elementary step (Rh n − + CO 2 and Rh n O − + H 2 ) requires to take place was identified.…”

Reverse water–gas shift catalyzed by RhnVO3,4− (n = 3–7) cluster anions under variable temperatures

“…CO 2 activation mediated by gas-phase clusters such as metal hydrides, metal oxides, and pure metal clusters, have been extensively studied. 12,[18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35] (The results since 2020 are listed in Table 1 and those before 2020 can be found in a review paper. 35 ) CO 2 hydrogenation is usually an endothermic process (e.g., RWGS, ΔH = +0.44 eV) and it is difficult to evaporate the tightly attached products (e.g., CO) or drive the resulting species to participate in subsequent transformations, thus, the catalysis of CO 2 hydrogenation has been scarcely established in gasphase studies.…”

“…35 ) CO 2 hydrogenation is usually an endothermic process (e.g., RWGS, ΔH = +0.44 eV) and it is difficult to evaporate the tightly attached products (e.g., CO) or drive the resulting species to participate in subsequent transformations, thus, the catalysis of CO 2 hydrogenation has been scarcely established in gasphase studies. 12,24,25,30 It is also challenging to identify the crucial step that determines the overall efficiency of catalysis, and the specifically sized clusters that can drive CO 2 hydrogenation under optimum conditions can hardly be defined. The Bowen group established the catalysis of CO 2 hydrogenation mediated with bimetallic hydrides PdCuH 2 − to catalyze CO 2 conversion into formic acid in combination with mass spectrometry, photoelectron spectroscopy, and theoretical calculations, and the elementary step that requires extra energy to complete the catalysis is the desorption of formic acid.…”