Pd loaded amphiphilic COF as catalyst for multi-fold Heck reactions, C-C couplings and CO oxidation

Abstract

COFs represent a class of polymers with designable crystalline structures capable of interacting with active metal nanoparticles to form excellent heterogeneous catalysts. Many valuable ligands/monomers employed in making coordination/organic polymers are prepared via Heck and C-C couplings. Here, we report an amphiphilic triazine COF and the facile single-step loading of Pd0 nanoparticles into it. An 18–20% nano-Pd loading gives highly active composite working in open air at low concentrations (Conc. Pd(0) <0.05 mol%, average TON 1500) catalyzing simultaneous multiple site Heck couplings and C-C couplings using ‘non-boronic acid’ substrates, and exhibits good recyclability with no sign of catalyst leaching. As an oxidation catalyst, it shows 100% conversion of CO to CO2 at 150 °C with no loss of activity with time and between cycles. Both vapor sorptions and contact angle measurements confirm the amphiphilic character of the COF. DFT-TB studies showed the presence of Pd-triazine and Pd-Schiff bond interactions as being favorable.

Low Band Gap Benzimidazole COF Supported Ni3N as Highly Active OER Catalyst

“…This COF, IISERP-COF1, was reported earlier by us [9] and its non-conducting character was verified from the four-probe measurements. This COF, IISERP-COF1, was reported earlier by us [9] and its non-conducting character was verified from the four-probe measurements.…”

“…[9] In brief, the powder pattern could be indexed well in a hexagonal crystal system in P6/m space group with high Figure of merit (FOM) and excellent fits were obtained using Pawley refinements. For this, we adopted a routine as in our earlier work.…”

“…For this, we adopted a routine as in our earlier work. [9] The layers of the COF, adopts an AAA… stacking giving rise to hexagonal shaped pores (27.0 Å) along the ab-plane (Figure 1, not factoring the van der Waals radii). The COF structure comprises of 2D structure built from hexagonal layers.…”

“…DOI: 10.1002/aenm.201601189 covalent oragnic frameworks (COFs) find use in gas storage, [2] hydrogen evolution, [3] proton conduction, [4] quantum sieving, [5] photoconductivity, [6,7] catalysis, [8,9] and sensing. [10] Many Schiff bond linked COFs, despite their diverse functionalization, form as wafer-thin hexagonal sheets resembling graphene.…”

“…[10] Many Schiff bond linked COFs, despite their diverse functionalization, form as wafer-thin hexagonal sheets resembling graphene. [8,9,11] Very recently, we demonstrated the high oxygen evolution reaction (OER) activity in a COF arising from the nanoscopic confinement of non-noble metal hydroxides within the mesopores of a N-rich COF. [8,9,11] Very recently, we demonstrated the high oxygen evolution reaction (OER) activity in a COF arising from the nanoscopic confinement of non-noble metal hydroxides within the mesopores of a N-rich COF.…”