Chakravarty, Amrita and De, Goutam (2016) Selective Cu4Pd alloy nanoparticles anchoring on amine functionalized graphite nanosheets and their use as reusable catalysts for a C-C coupling reaction with the sacrificial role of Cu for Pd-regeneration. Dalton Transactions, 45 (31). pp. 12496-12506. ISSN 1477-9226

PDF - Published Version Restricted to Registered users only Download (3646Kb) | Request a copy

Abstract

A facile method for the synthesis of phase selective alloy nanoparticles (NPs), Cu4Pd and their in situ anchoring on the surface of amine functionalized graphite nanosheets (AFGNS) by solvothermal process has been demonstrated. It has been seen that upon adding CuCl2 center dot H2O and PdCl2 into the reaction medium containing AFGNS, the -NH2 group initially helps to immobilize Cu2+ ions from CuCl2 center dot H2O. During the solvothermal reaction in presence of N,N-dimethylformamide (DMF; solvent cum reducing agent) Pd2+ gets reduced first due to its higher reduction potential. These Pd NPs in turn help in the reduction of Cu2+ to Cu in an epitaxial manner. Finally at high temperature and long reaction time Cu and Pd combine to form the Cu4Pd alloy NPs along with a small fraction of Cu NPs. The conditions to obtain Cu4Pd NPs have been optimized through controlled reactions. The as prepared Cu4Pd@AFGNS composite has been successfully used for Suzuki-Miyuara C-C coupling reaction with sufficiently high yield and reusability of up to five cycles. The progress of the reaction was monitored using a fluorimeter. Interestingly, it has been observed that the small fraction of the Cu NPs present in the system played a sacrificial role in regenerating metallic Pd NPs in the first and second reaction cycles, followed by Cu from the Cu4Pd alloy itself from the third cycle onwards which played the sacrificial role to regenerate Pd(0). A probable reaction mechanism of the catalytic reaction with Cu4Pd@AFGNS has been suggested.

Item Type:	Article
Subjects:	Engineering Materials
Divisions:	Nano-Structured Materials
Depositing User:	Bidhan Chaudhuri
Date Deposited:	11 Nov 2016 10:57
Last Modified:	11 Nov 2016 10:57
URI:	http://cgcri.csircentral.net/id/eprint/3732

Actions (login required)

View Item