Carbon nanotubes modified by multi-heteroatoms polymer for oxidative dehydrogenation of propane: Improvement of propene selectivity and oxidation resistance
Nanocarbon has been considered as a promising catalyst for oxidative dehydrogenation of propane (ODHP) due to its abundant reactive oxygen species, minimal carbon deposition and distinctive electronic and structural properties. Unfortunately, its further development has been restricted for a lengthy period due to its poor propene selectivity and low durability under high temperature or oxygen-rich conditions. To address these deficiencies, the hybrid catalysts composed of small amount of multi-heteroatoms N, P, S co-doping polymer (PZS) and oxidized carbon nanotubes (OCNTs) were prepared, which can achieve 63% propene selectivity at 14.3% propane conversion with catalytic stability over 20 h in ODHP reactions at 520 °C. This distinctive catalytic performance has reached the best level of reported doped nanocarbon catalysts. In addition, a series of kinetic experiments and structural characterizations on the proposed catalysts indicated that the material has superior oxidation resistance and strong ability to inhibit the formation of carbon oxides. The P–O and S–C species on the catalyst surface play a very important role in improving the propene selectivity and enhancing the oxidation resistance of OCNTs.