Jump to main content
Jump to site search


Tailoring the framework composition of carbon nitride to improve the catalytic efficiency of the stabilised palladium atoms

Author affiliations

Abstract

Graphitic carbon nitride (g-C3N4) exhibits unique properties for the preparation of single-atom heterogeneous catalysts (SAHCs) due to the presence of sixfold nitrogen-based coordination sites in the lattice. Despite the potential to profoundly affect the metal stabilisation and resulting catalytic properties, no work has previously investigated the effect of modifying the carrier composition. Here, we study the impact of doping carbon in g-C3N4 on the interaction with palladium. This is achieved by introducing carbon-rich heterocycles (barbituric acid or 2,4,6-triaminopyrimidine) during the synthesis of bulk and mesoporous g-C3N4. Palladium is subsequently introduced via microwave-irradiation-assisted deposition, which emerges as a highly effective route for the dispersion of single atoms. Detailed characterisation confirms the controlled variation of the C/N ratio of the lattice and reveals the complex interplay with the crystal size, surface area, amount of defects, basic properties and thermal stability of the carrier. Atomic dispersions of palladium with similar surface densities could be obtained on both the stoichiometric and carbon-doped carriers in mesoporous form, but appreciable differences are observed in the ratio of Pd2+/Pd4+. The latter, which provides a measure of the degree of electron transfer from the metal to the carrier, is found to correlate with the activity in the continuous flow semi-hydrogenation of 2-methyl-3-butyn-2-ol. Density functional theory calculations support the decreased adsorption energy of palladium upon doping with carbon and reveal the potentially significant impact of oxygen-containing defects. The findings demonstrate the importance of understanding the metal-carrier interaction to optimise the catalytic efficiency of SAHCs.

Graphical abstract: Tailoring the framework composition of carbon nitride to improve the catalytic efficiency of the stabilised palladium atoms

Back to tab navigation

Supplementary files

Publication details

The article was received on 26 May 2017, accepted on 12 Jun 2017 and first published on 12 Jun 2017


Article type: Paper
DOI: 10.1039/C7TA04607C
Citation: J. Mater. Chem. A, 2017, Advance Article
  •   Request permissions

    Tailoring the framework composition of carbon nitride to improve the catalytic efficiency of the stabilised palladium atoms

    E. Vorobyeva, Z. Chen, S. Mitchell, R. K. Leary, P. Midgley, J. M. Thomas, R. Hauert, E. Fako, N. López and J. Pérez-Ramírez, J. Mater. Chem. A, 2017, Advance Article , DOI: 10.1039/C7TA04607C

Search articles by author

Spotlight

Advertisements