Alumina supported copper oxide nanoparticles (CuO/Al2O3) as high-performance electrocatalysts for hydrazine oxidation reaction.

Direct hydrazine liquid fuel cell (DHFC) is perceived as effectual energy generating mean owing to high conversion efficiency and energy density. However, the development of well-designed, cost effective and high performance electrocatalysts is the paramount to establish DHFCs as efficient energy generating technology. Herein, gamma alumina supported copper oxide nanocatalysts (CuO/Al2O3) are synthesized via impregnation method and investigated for their electrocatalytic potential towards hydrazine oxidation reaction. CuO with different weight percentages i.e., 4%, 8%, 12%, 16% and 20% are impregnated on gamma alumina support. X-ray diffraction analysis revealed the cubic crystal structure and nanosized particles of the prepared metal oxides. Transmission electron microscopy also referred to the cubic morphology and nanoparticle formation. Electrochemical oxidation potential of the CuO/Al2O3 nanoparticles is explored via cyclic voltammetry as the analytical tool. Optimization of conditions and electrocatalytic studies shown that 16% CuO/Al2O3 presented the best electronic properties towards N2H2 oxidation reaction. BET analysis ascertained the high surface area (131.2546 m2 g1) and large pore diameter (0.279605 cm³ g-1) for 16% CuO/Al2O3. Nanoparticle formation, high porosity and enlarged surface area of the proposed catalysts resulted in significant oxidation current output (600 µA), high current density (8.2 mA cm-2) and low charge transfer resistance (3.7 kΩ). Electrooxidation of hydrazine on such an affordable and novel electrocatalyst opens a gateway to further explore the metal oxide impregnated alumina materials for different electrochemical applications.

Evaluation of Low and High Surface Area TiO2 and Al2O3 Metal Oxides-Carbon Hybrids in Terms of Polymer Electrolyte Membrane Fuel Cell Catalyst Support.

Support materials are of great interest in order to improve the activity and stability of the polymer electrolyte membrane fuel cell (PEMFC) catalysts. Metal oxides have been reported as promising support materials due to their excellent mechanical resistance and high stability against corrosion emerging at acidic and oxidative environment. In this study, high (250 m2/g) and low (45 m2/g) surface area mesoporous TiO2 and high (220 m2/g) and low (30 m2/g) surface area mesoporous Al2O3 were investigated as an alternate cathode catalyst support materials for PEMFCs. These semiconducting TiO2 and Al2O3 metal oxides were combined with the carbon black (Vulcan XC 72) at different mass ratios in order to preserve electrical conductivity of catalyst support a certain extent. Pt and TiO2/C and Pt and Al2O3/C catalysts were prepared by means of Pt reduction on support materials via microwave irradiation technique. The as-prepared catalysts were characterized with some physicochemical and electrochemical analyses. The results reveal that two surface areas TiO2 and Al2O3 support materials differ from each other in terms of fuel cell performance and high surface area TiO2/C (25:75) hybrid supported Pt catalyst gave the best performance.