Development of new supports for catalytic active phases is one of the most important research fields in heterogeneous catalysis, for use in many gas-phase and liquid-phase reactions.
Since the discovery of carbon nanotube, an increasing interest has been devoted to the preparation of new one-dimensional (1D) nanostructured materials such as nanowires or nanotubes – initiated from sp2 carbon and rapidly extended to oxides – for fundamental studies as well as for a wide range of applications. The field of catalysis also benefits from this (nano)material approach, and carbon nanotubes and nanofibers as well as high surface area silicon carbide (b-SiC) nanotubes obtained by a Shape Memory Synthesis process, used as catalytic active phase supports led to significant breakthroughs with interesting catalytic behaviors, due to their peculiar 1D morphology.
However, severe drawbacks are inherent to the use of fluffy 1D nanostructures, including an almost impossible recovery of the catalysts in liquid-phase medium, huge pressure drops and moving bed phenomena in fixed-bed reactors, and a health impact during handling. Therefore the macronisation of 1D catalysts is of great interest.
This talk details the synthesis, characterization and catalytic use of 1D carbon and b-SiC nanostructures, and focuses on the approach for designing safe and efficient macronized 1D carbon and b-SiC nanostuctures. A wide panel of environmental and energy impact target reactions is taken as key-reactions for highlighting the interest of using 1D carbon and b-SiC nanostructures as catalyst supports, in order to target new conversion and selectivity patterns. Supported by the development of a new electron tomography tool (3D microscopy) for getting more insight on the active phase location inside/outside of a nano-tube shaped support, the nanoreactor concept is pointed out, in which each carbon or b-SiC nanotube, either as fluffy or macronized material can be considered as a single nanoscale reactor. |