Hydrodechlorination of chloromethanes with Pd on activated carbon catalysts for the treatment of residual gas streams

Gas-phase hydrodechlorination of mixtures of chloromethanes with activated carbon-supported platinum catalysts

“…On the other hand, DCM conversion showed a significant increase with increasing space-time up to around 0.8 kg·h·mol -1 and beyond that value, no further significant increase was observed. This is consistent with previous results [13]. Hydrodechlorination of the mixture yielded mainly methane (SCH4 = 96.8-97.7%), and lower amounts of monochloromethane (SMCM = 1.1-1.9%) and ethane (SC2H6 = 0.7-1.6%).…”

“…The DCM conversion increased slightly and that of TCM decreased when increasing the DCM/TCM ratio beyond 2-3 in the inlet stream. This can be due to a competition between both compounds by the active centers of the catalyst [13]. However, the activity for both compounds was slightly lower than when working with each of them individually.…”

“…In addition, the small amount of electro-deficient Pt and the high dispersion and homogeneous distribution of Pt inhibit the formation of hydrocarbons of more than one carbon atom that may promote coke deposition. In previous studies, it was found that formation of hydrocarbons higher than methane is favored by the reaction of two chlorinated radicals adsorbed on adjacent electrodeficient metallic sites [13][14][15].…”

“…In previous studies [1,[13][14][15][16], we have investigated the HDC of individual chloromethanes (mainly DCM and TCM) using catalysts based on Pd, Pt, Rh and Ru supported on activated carbon. The catalysts were found to be effective in the HDC of DCM and TCM individually.…”

Deactivation behavior of Pd/C and Pt/C catalysts in the gas-phase hydrodechlorination of chloromethanes: Structure–reactivity relationship

“…Although HDC of CMs has been investigated to a lesser extent than HDC of other organochlorine compounds, several publications have appeared in recent years including a number reporting on the deep gas-phase HDC of CMs over different supported metal catalysts [4,5,[8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24]. It is well known that precious metals are active catalysts for the hydrogenolysis of the carbon-chlorine bond [8,9].…”