Bimetallic Ni‐Co Supported on Nitrogen‐Doped Carbon Nanotubes For Prox Reaction

Abstract

Abstract Hydrogen is a key component for a successful energy transition on a large scale since it boasts remarkable energy efficiency. Currently, H 2 is mainly obtained through steam reforming of natural gas or hydrocarbons and low‐carbon alcohols but contains approximately 2 % CO, a contaminant detrimental to H 2 fuel cells. Herein, an N‐doped carbon nanotube was prepared via the soft nitriding method to support nickel and cobalt for the PROX‐CO as the main reaction for hydrogen purification. The most efficient condition was achieved when the reaction temperature reached 250 °C and the Ni and Co loading rate was 7.5 %. In this situation, the CO 2 selectivity reached almost 33 %, and CO conversion was 61 %. Regarding CO conversion among bimetallic catalysts at 250 °C a minimal variation occurred and the catalyst 10Ni/N‐CNTs slightly outperformed (64.4 %). The effect of N‐doping on the carbon nanotube's structure was also revealed. Nitrogen atoms incorporated into the lattice of carbon nanotubes impart an electron‐donor character. Consequently, Co oxide reduction to the metallic phase occurred at significantly lower temperatures compared to other supports such as SiO 2 , Al 2 O 3 , and graphene. For the bimetallic catalysts, the strong metal‐support interaction facilitated obtaining different oxide and metallic phases at milder temperatures.