Synthesis strategies of carbon nanotube supported and confined catalysts for thermal catalysis

Enhancing the energy utilization efficiency through designing efficient materials is one of the most effective measures to combat the ever decreasing of fossil fuels, the deterioration of environment and the increasing of energy demands. Of particular interest is the carbon nanotubes (CNTs) confined catalysts because of the confinement effect in boosting the catalytic activity, selectivity and stability. To effectively and comparatively study the confinement effect, the synthesis methods to prepare nanoparticles confined within the channels or support on the exterior surface of CNTs are crucial. Therefore, in this review, these synthesis methods to prepare CNT confined catalysts such as wet chemistry method and in situ encapsulation method are compared and analyzed together with the methods, for instance, wet impregnation method and temporarily blocking method etc. to prepare nanoparticles supported on the exterior surface of CNTs. Additionally, their thermal catalysis applications are discussed and reasons lead to their outstanding performance are specifically analyzed. Finally, potential challenges and perspectives in designing CNT confined catalysts are proposed to inspire researchers and push forward their application in the field of energy and environmental science.