The selective oxidation of tetrahydrofuran to γ-butyrolactone is an efficient method to convert biomass derivatives into high-value chemicals. In order to improve the efficacy of conversion of tetrahydrofuran to γ-butyrolactone, this study prepared an Ag–CeO2/α-Al2O3 catalyst via the impregnation method and used a solvent-free approach to convert tetrahydrofuran to γ-butyrolactone. And the conversion rate of 100% of raw material was achieved. The prepared catalyst was characterized by TEM, XRD, N2 adsorption-desorption and XPS, in order to better understand the performance of the catalysts. The results demonstrated that Ce3+ and Ce4+ coexist on the surface of the catalyst and verified the existence of metallic Ag (Ag0) in Ag–CeO2/α-Al2O3 catalyst. The reaction mechanism of the formation of γ-butyrolactone by γ-site switch (ring-opening and ring-closing) of tetrahydrofuran was deduced. This is attributed to the synergistic action of Ag and Ce. γ-Site switch effect (ring-opening and ring-closing) is proposed for the first time in this paper. [ABSTRACT FROM AUTHOR]