Direct conversion of methane to oxygenates on porous organic polymers supported Rh mononuclear complex catalyst under mild conditions

Abstract

Converting CH4 to value-added products has been attracting more and more attention. However, most routes for CH4 catalytic conversion are performed at high temperature. Here we report a direct catalytic conversion process of CH4 on a Cu species promoted Rh mononuclear complex catalyst embedded on porous organic polymers (Rh1-Cu/POPs) under the atmosphere of CH4, CO and O2 at 150 °C in the aqueous solution. Through the combined characterization, mononuclear complex of (CH3)RhX(CO)(PPh3)2 was considered as the stay species, X denoted Cl or I. The iodine species participated the coordination of Rh mononuclear carbonyl complex and further promoted the transformation of CH3 to produce more oxygenated products, especially for the acceleration of acetic acid production. The space time yield of total oxygenated products, including CH3OH, HCOOH, HOCH2OH and CH3COOH, on iodine species promoted Rh1-Cu/POPs catalyst reached as high as 289.3 g/(kgcat ⋅h), recycled for five times without obvious decay.