CO temperature-programmed desorption of hexameric copper hydride nanoclusters catalyst supported on functionalized MWCNTs for kinetics study of low-temperature water-gas shift

Abstract

A novel catalyst made of crystallized hexameric copper hydride nanoclusters (Cu6) ligated with triphenylphosphine [(PPh3)CuH]6 deposited on functionalized multi-walled carbon nanotubes (MWCNTs) support is synthesized for a catalytic activity investigation in low-temperature water-gas shift (LTWGS) reaction. CO temperature-programmed desorption (CO-TPD) technique is employed to analyse the strength of the CO interacton with the catalyst surface, indicated by the CO desorption peak temperatures (lower temperature peak; weaker site and vice versa) and the breadth of the peak shoulders (broader shoulder; stronger site and vice versa). An actual LTWGS reaction run over the synthesized catalysts will be conducted to evaluate their actual performance based on CO conversion for the reaction kinetic study. The rate of reaction based on the catalyst sample that gives the highest CO conversion based on turnover frequency will be developed based on the expression derived from Moe or power-law model. A comparison of the activation energy value from the optimal catalyst developed in this work with the experimentally determined values from literature will be made. The overall finding will conclude if the LTWGS over the optimal Cu/MWCNTs catalyst follows regenerative/surface redox or Langmuir-Hinshelwood (LH) mechanism.