Dry Reforming of Methane to Syngas Mediated by Rhodium-Cobalt Oxide Cluster Anions Rh 2 CoO .
Xi-Guan ZhaoYan-Xia ZhaoQing-Yu LiuSheng-Gui HePublished in: The journal of physical chemistry letters (2024)
Dry reforming of methane (DRM) to syngas is an important route to co-convert CH 4 and CO 2 . However, the highly endothermic nature of DRM induces the thermocatalysis to commonly operate at high temperatures that inevitably causes coke deposition through pyrolysis of methane. Herein, benefiting from the mass spectrometric experiments complemented with quantum chemical calculations, we have discovered that the bimetallic oxide cluster Rh 2 CoO - can mediate the co-conversion of CH 4 and CO 2 at room temperature giving rise to two free H 2 molecules and two adsorbed CO molecules (CO ads ). The only elementary step requiring the input of external energy (e.g., high temperature) is desorption of CO ads from the reaction intermediate Rh 2 CoOC 2 O 2 - . The doping effect of Co has also been clarified that the Co could tune the charge distribution and orbital energy of the active metal Rh, enabling the enhancement of cluster reactivity toward C-H activation, which is essential to facilitating the DRM to syngas. This work not only underlines the importance of temperature control over elementary steps in practical thermocatalysis but also identifies a promising active species containing the late 3d transition metal to drive DRM to syngas. The findings could provide novel insights into design of bimetallic catalysts for co-conversion of CH 4 and CO 2 at low temperatures.
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