عنوان

Stabilization of Raney nickel catalyst for fuel cell electrodes

TLpq230951406

انگلیسی

Stabilization of Raney nickel catalyst for fuel cell electrodes

[Thesis]

S. M. M. J. Kareemuddin

King Fahd University of Petroleum and Minerals (Saudi Arabia)

1996

104

M.S.

King Fahd University of Petroleum and Minerals (Saudi Arabia)

1996

Two new methods namely, hydrogen peroxide oxidation and direct gas oxidation have been proposed and studied for the stabilization of Raney nickel catalyst used in fuel cell electrodes which eliminate the possibility of catalyst sintering that is usually encountered in conventional controlled surface oxidation method. Raney nickel catalyst needs to be stabilized as it contains adsorbed hydrogen on its active sites which has to be removed to avoid sintering. In conventional method, dried catalyst in vacuum oven is reacted with small doses of oxygen to remove the adsorbed hydrogen and to form a NiO layer on the catalyst. Hydrogen peroxide oxidation process utilizes the oxygen in the Husd\rm\sb2O\sb2usd to react with chemisorbed hydrogen. Direct gas oxidation process utilizes the pure oxygen or air to remove the adsorbed hydrogen. Characterization of the stabilized catalysts has also been done using SEM, XRD, BET surface and pore size distribution. The Husd\rm\sb2O\sb2usd stabilized catalysts have better active surface area, stable NiO content and good pore size distribution compared to conventional process. Direct gas oxidation catalysts have shown relatively less activity compared to conventional catalysts because of their unstable NiO content. Filtration method was used for preparing electrodes. Electrode performance has been found by using half cell arrangement connected to potentioscan interfaced with computer. Results showed that 15 wt.% Husd\rm\sb2O\sb2usd stabilized catalysts have shown better performance than the other electrodes. The direct gas oxidation electrodes have shown poor performance compared to conventional electrodes. Long term performance and reproducibility tests of 15 wt.% Husd\rm\sb2O\sb2usd stabilized electrodes have been carried out and found to be successful.

Applied sciences

Chemical engineering

Chemical engineering

Energy

S. M. M. J. Kareemuddin

p

[Thesis]

276903

a

Y