A series of CuO-ZnO-Al2O3 nanocatalysts were fabricated by microwave-assisted combustion method to investigate the role of propylene glycol/nitrates ratio. XRD, FESEM, FTIR, EDX, BET and TG techniques were applied to study the physicochemical properties of prepared nanocatalysts. It was found that increasing of fuel/ nitrates ratio decreased the specific surface area due to incomplete combustion reaction. TG and FTIR results proved that some combustion residuals such as nitrate species and propylene glycol remained in fabricated samples and their amount increased by increasing of fuel/nitrates ratio. Also, higher dispersion of CuO crystallites as the major active sites of steam methanol reforming achieved by CZA(PG/N = 1). So, it reached the complete conversion of methanol at lower temperature compared to the other samples. The synthesized sample with propylene glycol to nitrates ratio of 1 showed high stability during 1200 min. Moreover, the deactivation study was performed on best and worst synthesized nanocatalysts.