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Newly developed gas-diffusion electrodes (GDE) with binary catalyst composed of Ag and Pd were evaluated in a zero-gap type chlor-alkali cell. It was found that the cell voltage was 2.06V at 6kAm-2, which was 120 mV smaller than those of composed of single Ag catalyst or Pd catalyst. The increase of the cell voltage with the binary catalyst after 600 days of operation was only around 20 mV, which is one third of that of Ag catalyst. The particles sizes of the former catalyst were not changed after the electrolysis, but the size of Ag in the latter became large, which quantitatively corresponded to the increase of overvoltage predicted by a porous GDE model calculation. It was suggested that the agglomeration of the Ag catalyst could be inhibited by the existence of Pd.

Azo benzene derivatives are dispersed in a poly(carbonate) or poly(N-vinyl carbazole) matrix, and their photoconductive characteristics are investigated in terms of the structure of azo benzene derivatives and polymer matrix. These azo benzene derivatives are composed of electron donating and accepting parts bridged by azo bonds and are intramolecular charge transfer complexes as determined by UV-Vis spectra and electrochemical measurements. This charge transfer is effective for the increase of photoconduction in these derivative-dispersed poly(carbonate) films. When poly(N-vinyl carbazole) is used as a polymer matrix, photocurrent increases by one order of magnitude in comparison with that in a poly(carbonate) system. The roles of azo derivatives and polymers for photoconduction are discussed with the action spectrum of the photocurrent in these systems.

Newly developed gas-diffusion electrodes (GDE) with binary catalyst composed of Ag and Pd were evaluated in a zero-gap type chlor-alkali cell. It was found that the cell voltage was 2.06V at 6kAm-2, which was 120 mV smaller than those of composed of single Ag catalyst or Pd catalyst. The increase of the cell voltage with the binary catalyst after 600 days of operation was only around 20 mV, which is one third of that of Ag catalyst. The particles sizes of the former catalyst were not changed after the electrolysis, but the size of Ag in the latter became large, which quantitatively corresponded to the increase of overvoltage predicted by a porous GDE model calculation. It was suggested that the agglomeration of the Ag catalyst could be inhibited by the existence of Pd.