In situ adsorption-catalysis system for the removal of o-xylene over an activated carbon supported Pd catalyst.
An activated carbon (AC) supported Pd catalyst was used to develop a highly efficient in situ adsorption-catalysis system for the removal of low concentrations of o-xylene. In this study, three kinds of Pd/AC catalysts were prepared and tested to investigate the synergistic efficiency between adsorption and catalysis for o-xylene removal. The Pd/AC catalyst was first used as an adsorbent to concentrate dilute o-xylene at low temperature. After saturated adsorption, the adsorbed o-xylene was oxidized to CO2 and H2O by raising the temperature of the catalyst bed. The results showed that more than 99% of the adsorbed o-xylene was completely oxidized to CO2 over a 5% Pd/AC catalyst at 140 degrees C. Brunauer-Emmett-Teller (BET) analysis, scanning electron microscopy (SEM), temperature-programmed desorption (TPD), and temperature-programmed oxidation (TPO) were applied to investigate the physical properties of o-xylene adsorption-desorption and the in situ adsorption-catalysis activity of the AC support and Pd/AC catalyst. A synergistic relationship between the AC support and the active Pd species for the removal of low concentrations of o-xylene was established.
Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China. syhuang@rcees.ac.cn
Shaoyong
S
Huang
Changbin
C
Zhang
Hong
H
He
D000327:Adsorption; D000393:Air Pollutants / Q000737:chemistry*; D002384:Catalysis; D002606:Charcoal / Q000737:chemistry*; D007854:Lead / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D013696:Temperature; D014992:Xylenes / Q000737:chemistry*
D000393:Air Pollutants; D014992:Xylenes; D002606:Charcoal; D007854:Lead; C026114:2-xylene