The one-step gas-phase hydrogenolysis of dimethyl maleate to tetrahydrofuran has been investigated over a series of chromium-modified Cu-B/gamma Al2O3 catalysts prepared by the wetness impregnation-chemical reduction method. The characterizations reveal that copper in the Cu-B/gamma-Al2O3 and chromium-modified Cu-B/gamma-Al2O3 catalysts is solely in the metallic state, while chromium and boron are in the oxidized state. The addition of chromium not only reduces the crystallite size of metallic copper and increases the dispersion, but also promotes the intrinsic activity of the Cu-B/gamma-Al2O3 catalyst. With the aid of the acidity of gamma-Al2O3, a tetrahydrofuran yield of 94% is achieved over the 30% Cr-Cu-B/-gamma-Al2O3 catalyst under optimized reaction condition. (c) 2006 Elsevier B.V All rights reserved.