Silica coated with polyacrylonitrile (PAN) and heated at 200 degrees C for 8 h to stabilize the PAN by forming a fused ring structure, was used as support for copper catalysts. The catalysts were characterized by X-ray photoelectron spectroscopy (XPS) and temperature-programmed reduction (TPR), and also tested for methanol selective dehydrogenation to methyl formate (MF) in a fixed bed reactor. The coverage of silica by PAN was 0.126 mmol/100 m(2). The "monolayer spreading threshold value" of CuO on this support found by XPS was 0.31 mmol/100 m(2), which corresponds to 7.0 wt.-% of copper on the PAN/SiO2 support. This sample gave the optimal activity, selectivity, and MF yield for methanol dehydrogenation to MF of the samples with different copper contents. The optimal values are : 45.4% methanol conversion, 97.4% selectivity to MF, and 44.2% yield of MF, at 250 degrees C, atmospheric pressure, and a gas hourly space velocity (GHSV) 2220 h(-1) of argon containing 3.947.10(-3) MPa of methanol. The catalytic stability of Cu-PAN/SiO2 was much higher than that of Cu/SiO2(im) prepared by impregnation. The electron binding energy of Cu2p(3/2) in Cu-PAN/SiO2 is 1.0 eV lower than that in Cu/SiO2 and that of N1s in the catalyst sample is 1.5 eV higher than that in the support PAN/SiO2. It is inferred that electron transfer might have occurred from nitrogen to copper, forming a donor-acceptor binding and disperses as well as stabilizes the copper on the support surface. The surface Cu/Si atomic ratio of Cu-PAN/SiO2 is higher than that of Cu/SiO2(im). TPR of CuO-PAN/SiO2 samples gave a single peak at 210-260 degrees C, similar to those prepared by ion exchange using uncoated silica, but different from samples prepared by conventional impregnation on uncoated silica.