Effects of Tin on Product Distribution and Catalyst Stability in Hydrodechlorination of CCl₄ over Pt-Sn/γ-Al₂O₃

Abstract

The Pt-Sn/γ-Al 2 O 3 catalyst with a moderate amount of tin showed an enhanced catalytic stability and selectivity to CHCl 3 in hydrodechlorination of CCl 4 compared to monometallic platinum catalyst. The tin added in consecutive order to 1.0wt%Pt/γ-Al 2 O 3 acted as a diluting component of platinum ensemble sites and resulted in reducing the formation of C 2 compounds and carbon deposition. Furthermore, tin addition modifies the electronic state of supported platinum particles by the electron transfer from tin to platinum, results in the reduction of the binding energy of intermediate species, and suppresses the complete hydrodechlorination activity of surface intermediates. Thus on Pt-Sn/γ-Al 2 O 3 catalysts, adsorbed CCl 4 is readily desorbed as CHCl 3 instead of residing too long on the surface until it is completely dechlorinated to form CH 4 .

Pt–Sn/γ‐Al2O3‐Catalyzed Highly Efficient Direct Synthesis of Secondary and Tertiary Amines and Imines

“…In addition, the presence of tin in the bimetallic Pt–Sn/γ‐Al 2 O 3 catalyst modifies the electronic state of the supported Pt particles by electron transfer from tin to platinum. This results in reduction of the binding energy of the intermediate species and products thus, suppresses further reactions of some chemical bonds 16c. The γ‐Al 2 O 3 support usually shows Lewis acidity, highly desired in our case, to facilitate condensation of the aldehyde/ketone intermediates with amines to generate imines.…”

Understanding the Role of NbOx on Pt/Al2O3 for Effective Catalytic Propane Oxidation

“…The reduction peak α at low temperatures should be related to PtO x with a weak interaction to Al 2 O 3 . High-temperature reduction peak β represents that the PtO x is relatively difficult to be reduced due to the strong interaction between the PtO x and Al 2 O 3 support. , Both α and β peaks slightly shift to higher temperatures with increasing NbO x loadings, suggesting that the PtO x species become more stable and difficult to be reduced. The area of the reduction peak α increases as the NbO x loading increases up to 6.0 wt %, and it decreases when the NbO x content further increases.…”

Enhanced activity of carbon-supported Pd–Pt catalysts in the hydrodechlorination of dichloromethane

“…In the last years, in order to improve their properties, an increasing number of catalysts whose active phases include more than one metal are being used for the sake of combining their respective abilities with better results in terms of behaviour and economy [23][24][25][26][27].…”