Anti-sulfur poisoning of rare-earth catalyst in sensors

Based on theoretical analysis and experimental research the present paper has mainly investigated the anti-sulfur poisoning action of common rare-earth oxide such as CeO{sub 2} in gas sensors containing Pt/Al{sub 2}O{sub 3}. Experiments show that RE promoters can effectively modify Pt/Al{sub 2}O{sub 3} catalyst, inhibit sulfur poisoning and maintain high catalytic activity for methane conversion in air containing H{sub 2}S. Mechanism of anti-sulfur poisoning is discussed tentatively and anti-sulfur poisoning is explained through absorption of poison molecule by RE with high priority. Simultaneously, the carrying reaction of transformation and formation of RE sulfate makes the poison inactive.