Catalytic conversion mechanism of guaiacol as the intermediate of lignin catalytic pyrolysis on MgO surface: Density functional theory calculation

•The most stable structures of guaiacol and products on clean and H-adsorbed MgO(100) surfaces are determined.•Hydrogen bond is generated between the O1 atom of guaiacol molecule and the pre-adsorbed H atom.•Hydrogen bond promotes the adsorption of guaiacol molecule on the MgO(100) surface.•The presence of hydrogen atom on the MgO(100) surface can promote the conversion of guaiacol.