Toward Rational Design of Nickel Catalysts for Thermocatalytic Decomposition of Methane for Carbon Dioxide‐Free Hydrogen and Value‐Added Carbon Co‐Product: A Review

Abstract

Thermocatalytic decomposition of methane provides opportunities for hydrogen (H2) production with no emission of carbon dioxide. However, high‐value carbon products need to be produced for economic deployment of thermocatalytic decomposition and to achieve a minimum H2 selling price below the U.S, Department of Energy target of $1/kg H2. In this review, we re‐evaluate data on catalyst development reported in the literature and propose fundamental correlations between catalyst characteristics, catalytic stability, and properties of carbon co‐products. In the first part of the review, growth mechanisms for carbon nanotubes using state‐of‐the‐art chemical vapor deposition are reviewed to catalog the effects of catalyst characteristics, the influence of carbon sources, interactions between metal particles and supports, and metal particle sizes on carbon growth. In the second part, representative developments in mono‐, bi‐, and tri‐metallic nickel catalysts are highlighted. We present kinetic analysis of reactions catalyzed by mono‐metallic nickel catalysts, which generates a correlation between metal particle size and catalyst stability.