Regeneration of Aged Commercial Three-Way Catalysts Using CI-Containing Reagents

Metal Redispersion Strategies for Recycling of Supported Metal Catalysts: A Perspective

“…A structured monolith Pd–Rh three-way catalyst was also treated with chlorine reagents (1,2-dichloropropane and dichloroacetic acid) using 0.1 M solutions flowing at 0.6 L min –1 at 50 °C for 2 h, a procedure that has been reported before for the regeneration of other monolith samples via removal of poisons. , The dichloroacetic acid was found to be more effective than dichloropropane at recovering Pd active sites, which has been attributed to the apparent redispersion and restructuring of said Pd due to the chlorination and subsequent reduction. This redispersion had the additional benefit of recovering oxygen storage capacity, as has been noted in a number of cases.…”

Phosphorus poisoning during wet oxidation of methane over Pd@CeO2/graphite model catalysts

“…Cerium phosphate is also very stable and cannot be removed from either pure CeO 2 or Ce x Zr 1-x O 2 by calcination treatments to 1000 °C [21,26]. A few studies indicated partial removal of phosphate species by washing the spent catalyst with oxalic acid [18] or chlorine containing species [27]. However, CePO 4 persists even after these treatments [18], implying that alternative methods need to be developed to address the problem of P-poisoning.…”

Regeneration of commercial selective catalyst reduction catalysts deactivated by Pb and other inorganic elements

“…Regeneration of three-way automobile catalysts (TWCs) and other catalysts has drawn much attention in recent years. (López et al, 2011;Christou et al, 2006Christou et al, , 2007Subramanian et al, 2011;Christou and Efstathiou, 2013). However, research on regeneration of SCR catalysts has been limited.…”