Catalytic pyrolysis of lignocellulosic biomass generates water-soluble low-molecular-weight oxygenates such as acetic acid, acetone, furfural, butanone, guaiacol, phenol, etc. These compounds are usually not suitable for conventional hydrocarbon fuel applications. A new heterogeneous catalyst has been developed that simultaneously catalyzes alkylation, hydrodeoxygenation, and hydrogenation of these small oxygenate molecules in aqueous media to produce C-6 to C-14 hydrocarbons in a one-pot synthesis. In these syntheses, acetic acid, propionic acid, furfural, butanone, pentanone, heptanone, and 2,6-dimethyl-4-heptanone reacted to produce straight- and branched-chain alkanes. The aldehydes reacted with furan to form straight-chain liquid hydrocarbons, while the ketones reacted with 2-methylfuran to produce branched-chain liquid hydrocarbons. All the reactions occurred in aqueous media at 350 degrees C. The gaseous products included low-molecular-weight hydrocarbons such as methane, propane, butane, and pentane.