CO is a toxic gas, also as an abundant C1 building block. Catalytic conversion of CO is a subject of extensive interest in heterogeneous catalysis. CO in the presence of H2 is well utilized for the industrial manufacture of methanol through Fischer–Tropsch process. Meanwhile, alkylated aromatics as important petrochemical commodities for agrochemicals and pharmaceuticals can be obtained from acid-catalyzed alkylation of aromatics with methanol. Thus, the direct use of CO as an alkylating reagent would be of considerable interest for both synthesis of alkylbenzenes and efficient utilization of CO.
By controlling the local structure of Zn species on Zn modified HZSM-5 zeolite, Associate Prof. Jun Xu and Dr. Xiumei Wang realized the direct alkylation of benzene with CO to form toluene. According to in-situ solid-state NMR spectroscopy studies, CO can be converted into the surface methoxy species, which act as an intermediate interacting with benzene to produce toluene. CO provides the methyl groups while benzene affords the phenyl ring of the substituted product. The alkylating role of CO presented here implies that, apart from its well-known carbonylating/acylating ability, CO could be selectively converted into the desired functional group of the final product by pre-activation of CO into specific intermediates over acidic zeolites.
In the previous work, using in situ solid-state NMR in combination with various spectroscopic techniques, Prof. Deng Feng’s group has successfully revealed the mechanisms of the activation and transformation of methane and carbon monoxide over Zn-modified zeolite catalysts (Angew. Chem. Int. Ed. 2012, 51, 3850；Chem. Sci. 2012, 3, 2932；J. Am. Chem. Soc. 2013, 135, 6762；J. Phys. Chem. C, 2013, 117, 4018).
This work was supported by the National Natural Science Foundation of China and the Wuhan Science and Technology Bureau‘Chen Guang’ project.
(Pan Gao)
