Low-density xSiO2-(1-x)Al2O3 xerogels with x=0.9, 0.8, 0.7, 0.6 (mole fractions) were
prepared by sol-gel and non-supercritical drying. Silica alkogels, which were the framework of binary
composite materials, formed from tetraethyl orthosilicate (TEOS) by hydrolytic condensation with a
molar ratio of TEOS: H2O: alcohol: hydrochloric acid: ammonia =1: 4: 10: 7.5×10-4: 0.0375. Aluminum
hydroxide derived from Al(NO3)3·9H2O and NH4OH acting in the alcohol solution under the condition of
catalyst. After filtrating and washing, the precipitation was mixed into silica sols to form SiO2-Al2O3
mixed oxide gels with different silicon and aluminum molar ratio. The structural change and
crystallization of the binary xerogels were investigated after heat treatment at 600 for 2 h by the means
of X-ray diffraction. Nitrogen adsorption experiment was performed to estimate specific surface area,
porous volume and pore size distribution. The structural change of xerogels was observed by FT-IR
spectroscopy. The resulting mixed xerogels possess of mesoporous structure which is characteristic of
cylindrical pores, high specific surface area of 596-863 m2/g and a relatively narrow pore distribution of
2.8-30 nm. Al2O3 is introduced into the SiO2 phase and some of Al-O-Si bonds form.
Preparation of small-sized tungsten carbide nanorods for loading Pt with promoted electrocatalytic activity and stable anti-poisoning performance
