METHOD FOR WATER-REPELLENCY TREATMENT OF CATALYST FOR OXIDATION OF HYDROGEN Russian patent published in 1995 - IPC

FIELD: catalytic chemistry. SUBSTANCE: catalyst is subjected to heat treatment at temperature of 575-580 K with subsequent contacting in vacuum, first, tetrafluoroethylene (water-repellent agent) for 4.5-5 h; freezing down to temperature of liquid nitrogen at the rate of 5-7 K/min; exposure to gamma-radiation with dose of 0.5-3 Mrad; defrosting at room temperature with removal of unreacted tetrafluoroethylene; contacting hexafluoropropylene for 5-6 h; removal of its excess; heating up to 610-620 K; holding for 15-20 min and cooling at the rate of 0.5-1 K/min down to room temperature. In this event, produced catalyst is able to oxidize trace amounts of hydrogen into water in closed objects at humidity above 70% and moderate temperatures, as in the known case flow rate of gas mixture does not exceed 3 l/h with temperature maintained in the reaction layer of 80 C. With concentration of hydrogen of 3 vol. and conversion of 95% hydrogen overshoot amounts to 0.15, and in the present case, with hydrogen content of 0.09 vol. and conversion of 97.8% hydrogen overshoot amounts to 0.002 vol. EFFECT: higher activity of catalyst at ambient relative humidity in excess of 70% 2 tbl