A photocatalytic nonoxidative coupling of methane to multi-carbon compounds remains a huge challenge due to its high dissociation energy of C–H bonds and sluggish charge carrier dynamics.Au-modified carbon-doped ZnO(...A photocatalytic nonoxidative coupling of methane to multi-carbon compounds remains a huge challenge due to its high dissociation energy of C–H bonds and sluggish charge carrier dynamics.Au-modified carbon-doped ZnO(C-ZnO/Au)photocatalyst is constructed by an interfacial modification-assisted self-assembly approach for efficient photocatalytic nonoxidative coupling of methane to ethylene and hydrogen(2CH_4=C_2H_4+2H_2).Benefitting from the presence of C-ZnO/Au interfaces,the catalyst not only weakens the excitonic confinement to improve the photogenerated charge carrier separation,but also enhances the stability of lattice oxygen to suppress C_2H_4 overoxidation.Moreover,this hybrid catalyst also accelerates the generation of Zn~+–O~–pairs to activate C–H bonds,stabilizes the important reaction intermediate(*OCH_3)to achieve the C–C coupling,and promotes the generation of low-valence Zn to accelerate the dehydrogenation of the*OC_2H_5 into C_2H_4.Therefore,a stable photocatalytic methane conversion performance can be achieved over C-ZnO/Au heterojunctions with a stoichiometric generation of the oxidation product(C_2H_4,45.85μmol g~(-1)h~(-1))and reduction product(H_2,88.07μmol g~(-1)h~(-1)).This work provides deep insights into the elemental doping and oxide/Au interfaces for the enhanced photocatalytic activity and product selectivity under mild conditions in the absence of extra oxidants.展开更多
基金the funding support from the National Natural Science Foundation of China(22272120,U2202251 and 92045302)the Fundamental Research Funds for the Central Universities(2042022kf1174 and 2042021kf0213)。
文摘A photocatalytic nonoxidative coupling of methane to multi-carbon compounds remains a huge challenge due to its high dissociation energy of C–H bonds and sluggish charge carrier dynamics.Au-modified carbon-doped ZnO(C-ZnO/Au)photocatalyst is constructed by an interfacial modification-assisted self-assembly approach for efficient photocatalytic nonoxidative coupling of methane to ethylene and hydrogen(2CH_4=C_2H_4+2H_2).Benefitting from the presence of C-ZnO/Au interfaces,the catalyst not only weakens the excitonic confinement to improve the photogenerated charge carrier separation,but also enhances the stability of lattice oxygen to suppress C_2H_4 overoxidation.Moreover,this hybrid catalyst also accelerates the generation of Zn~+–O~–pairs to activate C–H bonds,stabilizes the important reaction intermediate(*OCH_3)to achieve the C–C coupling,and promotes the generation of low-valence Zn to accelerate the dehydrogenation of the*OC_2H_5 into C_2H_4.Therefore,a stable photocatalytic methane conversion performance can be achieved over C-ZnO/Au heterojunctions with a stoichiometric generation of the oxidation product(C_2H_4,45.85μmol g~(-1)h~(-1))and reduction product(H_2,88.07μmol g~(-1)h~(-1)).This work provides deep insights into the elemental doping and oxide/Au interfaces for the enhanced photocatalytic activity and product selectivity under mild conditions in the absence of extra oxidants.
