Catalytic Activity of Cе-, Zr- and Mn-Containing Oxide Layers on Titanium in the Process of Biomass Gasification
Composition, surface structure (also after annealing at high temperature) and the catalytic activity in the steam conversion of naphthalene were studied with Ce-, Zr- and Mn-containing oxide layers obtained by means of plasma electrolytic oxidation on titanium. The composition and structure of oxide systems were studied by means of X-ray phase, energy dispersion analysis and scanning electron microscopy. It was shown that Ce-, Zr-containing structures possess rather high thermal stability: elemental, phase composition, structure of their surface remain almost unchanged after annealing in the air at a temperature up to 800 °C. Catalytic studies demonstrated rather high activity of Ce-, Zr-containing coatings in the reaction of steam conversion of naphthalene at temperatures up to 850 °С. Mn-containing oxide structures have developed surface covered with nanowhiskers that were not detected after thermal treatment. Mn-containing oxide systems exhibited the lower degree of naphthalene conversion in comparison with Се-, Zr-containing coatings, which can be connected with substantial changes of their surface and the formation of low-active fused manganese silicates at high temperature.