Metal-free aerobic oxidation of benzyl alcohols over the selective N, P dual-doped hollow carbon sphere as the efficient and sustainable heterogeneous catalyst under mild reaction condition

Abstract

Nitrogen and phosphorous dual-doped carbon materials are one the promising candidate for the ecofriendly and metal-free heterogeneous catalytic systems owing to the abundance activated sites which is caused by doping the heteroatoms in the carbonaceous materials. The N, P-dual-doped carbon hollow sphere (HPNC-700) precursor prepared via template-assisted strategy by using the SiO 2 as the hard template in the presence of glucose, phosphoric acid and melamine as C, P, and N source, respectively. The resultant catalyst was obtained by pyrolyzing process at 700 °C under N 2 atmosphere by adding the NaOH solution to remove the template. According to various physicochemical analysis including FE-SEM, TEM, XRD, XPS, and Raman spectroscopy, the catalyst exhibited the desired and acceptable properties. So, based on these outcomes, the catalytic efficiency of the HPNC-700 was evaluated in the selective aerobic oxidation of benzyl alcohols. As expected, the HPNC-700 represented the acceptable proficiency in the mentioned reaction with high TOF value, full conversion (>99%) and also the notable recyclability. • P, N-dual doped carbon hollow spheres were designed for selective aerobic oxidation of benzyl alcohols. • SiO 2 spheres were used as the hard templet to synthesis the hollow spheres. • The heterogeneous metal-free HPNC-700 catalyst represents the high efficiency toward oxidation reaction at mild condition. • The more defects in the carbonaceous caused the more efficiency in the catalytic performance. • By doping The P and N in the sructure of carbon, the activated sites were developed in the synthesized catalyst.