Key Laboratory of Green Chemical Process of Ministry of Education, Key Laboratory of Novel Reactor and Green Chemical Technology of Hubei Province, Engineering Research Center of Phosphorus Resources Development and Utilization of Ministry of Education, School of Chemical Engineering and Pharmacy, Wuhan Institute of Technology, Wuhan430205, P. R. China.
School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou510641, P. R. China.
Langmuir. 2023 Feb 14;39(6):2422-2434. doi: 10.1021/acs.langmuir.2c03305. Epub 2023 Feb 3.
Partial oxidation of methane (CH) to methanol (CHOH) remains a great challenge in the field of catalysis due to its low selectivity and productivity. Herein, Ag-O-Ag/graphene and Cu-O-Ag/graphene composite catalysts are proposed to oxidize methane (CH) to methanol (CHOH) by using the first-principles calculations. It is shown that reactive oxygen species (μ-O) on both catalysts can activate the C-H bond of CH, and in addition to CH activation, the catalytic activity follows the order of Ag-O-Ag/graphene (singlet) > Ag-O-Ag/graphene (triplet) ≈ Cu-O-Ag/graphene (triplet) > Cu-O-Ag/graphene (singlet). For CHOH* formation, the catalytic activity follows the order of Cu-O-Ag/graphene (triplet) > Ag-O-Ag/graphene (triplet) > Ag-O-Ag/graphene (singlet) > Cu-O-Ag/graphene (singlet). It can be inferred that the introduction of Cu not only reduces the use of noble metal Ag but also exhibits a catalytic effect comparable to that of the Ag-O-Ag/graphene catalyst. Our findings will provide a new avenue for understanding and designing highly effective catalysts for the direct conversion of CH to CHOH.
甲烷（CH）部分氧化为甲醇（CHOH）在催化领域仍然是一个巨大的挑战，因为其选择性和产率都很低。本文提出了 Ag-O-Ag/石墨烯和 Cu-O-Ag/石墨烯复合催化剂，通过第一性原理计算将甲烷（CH）氧化为甲醇（CHOH）。结果表明，两种催化剂上的反应性氧物种（μ-O）都可以激活 CH 的 C-H 键，除了 CH 的活化之外，催化活性顺序为 Ag-O-Ag/石墨烯（单重态）>Ag-O-Ag/石墨烯（三重态）≈Cu-O-Ag/石墨烯（三重态）>Cu-O-Ag/石墨烯（单重态）。对于 CHOH*的形成，催化活性顺序为 Cu-O-Ag/石墨烯（三重态）>Ag-O-Ag/石墨烯（三重态）>Ag-O-Ag/石墨烯（单重态）>Cu-O-Ag/石墨烯（单重态）。可以推断，引入 Cu 不仅减少了贵金属 Ag 的使用，而且表现出与 Ag-O-Ag/石墨烯催化剂相当的催化效果。我们的发现将为理解和设计高效催化剂提供新途径，以实现 CH 到 CHOH 的直接转化。
