US EPA

1125468 

Journal Article 

SULFUR POISONING OF SUPPORTED PALLADIUM METHANOL SYNTHESIS CATALYSTS 

Berube, MN; Sung, B; Vannice, MA 

1987 

Yes 

Applied Catalysis
ISSN: 0166-9834 

Elsevier 

31 

1 

133-157 

10.1016/S0166-9834(00)80672-7 

https://linkinghub.elsevier.com/retrieve/pii/S0166983400806727
Exit
 

The deactivation of Pd dispersed on SiO2, n-Al2O3, silica-alumina, TiO2 and Nd2O3 was studied in the presence of 2 ppm H2S during CO hydrogenation at 523 K, 1.5 MPa and a H2/CO ratio of 3. First, the activity and selectivity of these catalysts in the absence of sulfur were established over long times on stream. Pd/SiO2 and Pd/Nd2O3 were found to be the most selective to methanol while high-temperature reduced Pd/TiO2 was the most active CO hydrogenation catalyst, producing CH3OH, CH4 and CH3OCH3. The addition of H2S in the feed typically reduced methanation activity by only about 50% over the time periods studied (40–250 h), but essentially all the oxygenate activity was lost, which resulted in a marked selectivity shift to methane. There was one notable exception, namely Pd/SiO2, which proved to be more tolerant to sulfur poisoning than the other catalysts as it stabilized at about 40% of its initial methanol activity. In comparison to poisoning studies of other metals such as Ni, Co, Fe and Ru, these Pd catalysts maintain much higher specific activity levels in the presence of comparable (or higher) H2S levels. The selective poisoning of oxygenate formation, compared to methanation, is strong evidence that at least two different types of active sites exist for CO hydrogenation.