Direct synthesis of dimethyl ether (DME) by CO 2 hydrogenation has been investigated over three hybrid catalysts prepared by different methods: co-precipitation, sol-gel, and solid grinding to produce mixed Cu, ZnO, ZrO 2 catalysts that were physically mixed with a commercial ferrierite (FER) zeolite. The catalysts were characterized by N 2 physisorption, X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), temperature programmed desorption of CO 2 (CO 2 -TPD), temperature programmed desorption of NH 3 (NH 3 -TPD), and temperature programmed H 2 reduction (H 2 -TPR). The results demonstrate that smaller CuO and Cu crystallite sizes resulting in better dispersion of the active phases, higher surface area, and lower reduction temperature are all favorable for catalytic activity. The reaction mechanism has been studied using in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). Methanol appears to be formed via the bidentate-formate (b-HCOO) species undergoing stepwise hydrogenation, while DME formation occurs from methanol dehydration and reaction of two surface methoxy groups. Image 1 [ABSTRACT FROM AUTHOR]