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Abstract: A series of aluminumphosphate molecular sieves supported platinum–cobalt catalysts were prepared and tested for the preferential oxidation of CO in H2-rich gases. The catalysts were characterized by XRD, HRTEM, EDX, TPR and XPS techniques. The optimized catalysts were highly active and selective, CO could be purified below 10ppm in the reaction temperature range of 110°C–125°C under 1% CO, 1% O2, 12.5% CO2, 15% H2O, 50% H2 in volume and N2 balance at the space velocity of 24,000mLgcat −1 h−1 . Pt–Co/CoAPO-5 exhibited the best catalytic performance and Pt–Co/AlPO-5 was the most active catalyst at low reaction temperature, in which particles of Pt–Co alloy were formed and the particles were highly dispersed on the surface of the support. The high activity could be attributed to the Pt–Co nano-partilces with small sizes. The enlarged temperature window for CO purification should be ascribed to the loaded cobalt oxide. Substitution of cobalt ions for aluminium ions has obvious influence on the interaction between the support and platinum/cobalt species. [Copyright &y& Elsevier]

Abstract: The hydrogen adsorption simulations were carried for several model AlPOs (VPI-5, AlPO-5, AlPO-11 and AlPO-25) employing the Grand Canonical Monte Carlo (GCMC) simulations at 77K to investigate the effect of pore size and the pore volume on the hydrogen uptake. The adsorption capacity showed no relationship with the pore size, surface area and micropore volume of AlPOs. However, the adsorption capacity per unit micropore volume increased as the pore size decreases. The heat of adsorption also increased as the pore size decreases. For all model AlPOs, the hydrogen exists homogeneously near the oxygen atoms in the framework. [Copyright &y& Elsevier]

Medium pore aluminophosphate-based molecular sieves like AlPO-41, CoAPO-41, CoAPSO-41 and MnAPSO-41 have been synthesised hydrothermally using dipropylamine as the organic template. These materials have been characterised by various physical methods including X-ray powder diffraction (XRD), thermogravimetric analyses (TGA), FT-IR, ESR and scanning electron microscope (SEM). All these materials are found to be crystalline and do not contain any detectable impure phases. The catalytic performance of these materials has been examined for ethylation of ethylbenzene with ethanol at 250, 300, 350, 400 and 450 °C. Ethylbenzene conversion is observed to increase with increase in temperature with the maximum conversion at 400 °C. The major product is 1,4-diethylbenzene whose selectivity decreases with increase in temperature over all the catalysts. High temperature is favourable for the formation of 1,3-diethylbenzene which is thermodynamically more stable than the other products. Influence of feed ratio on conversion and products selectivity is examined and the results are discussed in this paper. [Copyright &y& Elsevier]