Abstract
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•Thermal treatment of MOF Ru-MIL-140C-10 gave a novel catalyst for CO2 conversion.•The catalyst consisted of Ru and ZrO2 nanoparticles dispersed on carbon ribbons.•H2/CO2 (3:1) was selectively converted to CH4 for more than 82 h of reaction.•CH4 production of 53 mol/g Ru/h (350 °C, 40 bar, WHSV 344 L/h/g cat) was achieved.
A novel material, designated Ru/ZrO2@C(MIL), was prepared by thermal transformation of metal organic framework (MOF), MIL-140C-10, in which 10 % of the conventional biphenyl-dicarboxylate linkers had been substituted with bipyridyl-dicarboxylate linkers, thereby providing sites for Ru coordination with the framework. This MOF precursor was compositionally and morphologically transformed when heated, at 500 °C, in a mixture of H2 and CO2 (3:1). The transformation afforded a high surface area product (114 m2/g) with exceptional stability and high Ru metal dispersion which was very effective as catalyst for the hydrogenation of CO2 to CH4, giving a CH4 production of 53 mol/g Ru/h (at 350 °C, 40 bar and WHSV 344 L/h/g cat.). TEM results show that the active form of the catalyst was a partially degraded (‘unzipped’) MOF structure where Ru° and ZrO2 nanoparticles (2−5 and 10−20 nm diameter, respectively) were dispersed upon carbonaceous ribbons.