NITROGEN-CONTAINING CARBON NANOTUBES AS AN EFFECTIVE SUPPORT FOR THE SYNTHESIS OF STABLE SINGLE ATOM METAL CATALYSTS

The possibility of using nitrogen-containing carbon nanotubes (N-CNTs) as a support for the synthesis of single atom palladium and platinum catalysts has been studied. The influence of metal content (0.2-2 wt%) and synthesis method (impregnation and deposition) on the dispersion of supported Pd and Pt was studied. The requirements for preparation of a 100 % single atom catalyst have been determined (use of a metal precursor in cationic form and a metal content of less than 0.5 wt%). It was established that the turnover frequency of the gas-phase formic acid decomposition reaction for hydrogen production increases by 4 times on single metal atoms stabilised on the pyridinic nitrogen centres of N-CNTs, compared to nanoparticles with a size of ~1 nm. Single atom metal catalysts exhibit higher selectivity to hydrogen and make it possible to decrease the concentration of carbon monoxide by more than 2 times. The stability of Pd and Pt atomic species in the course of the reaction occurring at elevated temperatures has been established.