Heterogeneous halide-free carbonylation of methanol to acetates,including methyl acetate(MA)and acetic acid,using non-precious metal catalysts has been a topic of interest for decades.The key issue is that the water p...Heterogeneous halide-free carbonylation of methanol to acetates,including methyl acetate(MA)and acetic acid,using non-precious metal catalysts has been a topic of interest for decades.The key issue is that the water produced by methanol dehydration inhibits the formation of acetyl species and reduces the MA selectivity.Here,we report that CuCeO_(x)/H-mordenite(H-MOR)catalyst can nearly eliminate the inhibiting effect of water on carbonylation by a water-gas shift reaction(WGSR)on-site,and can thus achieve 96.5%methanol conversion with 87.4%MA selectivity for the halide-free carbonylation of methanol.The results of powder X-ray diffraction,transmission electron microscopy,and scanning electron microscopy show that the Cu and Ce species are highly dispersed on H-MOR even when the CuCeO_(x)contents are as high as 29 wt-%.Fourier transform infrared spectroscopy and CO chemisorption analysis reveal that a small portion of Cu species can migrate into the channel of H-MOR when CuCeO_(x)/H-MOR is calcined at 500℃and these Cu species are converted into Cu^(+) sites upon reduction.The Cu^(+) sites facilitate the WGSR and are also active sites for methanol carbonylation.The introduction of Ce benefits the inhibition of coke deposits and thus enhances the catalyst stability.展开更多
基金the National Key Research and Development Program of China(Grant Nos.2018YFB0604703,2017YFA0206801,and 2018YFB0604701)the National Natural Science Foundation of China(Grant Nos.21972113 and 91545115)+1 种基金the Program for Innovative Research Team in Chinese Universities(Grant No.IRT_14R31)the Fundamental Research Funds for the Central Universities(Grant No.20720190039).
文摘Heterogeneous halide-free carbonylation of methanol to acetates,including methyl acetate(MA)and acetic acid,using non-precious metal catalysts has been a topic of interest for decades.The key issue is that the water produced by methanol dehydration inhibits the formation of acetyl species and reduces the MA selectivity.Here,we report that CuCeO_(x)/H-mordenite(H-MOR)catalyst can nearly eliminate the inhibiting effect of water on carbonylation by a water-gas shift reaction(WGSR)on-site,and can thus achieve 96.5%methanol conversion with 87.4%MA selectivity for the halide-free carbonylation of methanol.The results of powder X-ray diffraction,transmission electron microscopy,and scanning electron microscopy show that the Cu and Ce species are highly dispersed on H-MOR even when the CuCeO_(x)contents are as high as 29 wt-%.Fourier transform infrared spectroscopy and CO chemisorption analysis reveal that a small portion of Cu species can migrate into the channel of H-MOR when CuCeO_(x)/H-MOR is calcined at 500℃and these Cu species are converted into Cu^(+) sites upon reduction.The Cu^(+) sites facilitate the WGSR and are also active sites for methanol carbonylation.The introduction of Ce benefits the inhibition of coke deposits and thus enhances the catalyst stability.
