Preparation of a new B-CNTs/PSSF composite catalyst for catalytic wet peroxide oxidation of phenol in structured fixed bed

A new structured catalyst consisting of boron-doped carbon nanotubes growing directly on paper-like stainless steel fibers support (B-CNTs/PSSF) was developed for continuous catalytic wet peroxide oxidation (CWPO) of phenol in a structured fixed bed. Firstly, B-CNTs/PSSF was synthesized by chemical vapor deposition (CVD) with phenyboronic acid as a single precursor and CNTs/PSSF was prepared with camphor for comparison. Secondly, the effects of different deposition temperatures, deposition times, and phenylboronic acid dosages on the morphology and properties of B-CNTs were investigated, respectively. The results verified that under the conditions of deposition temperature of 750 °C, deposition time of 20 min, and phenylboronic acid dosage of 2 g, the B-CNTs/PSSF composite catalyst with uniform growth density, wavy and kinked morphology, abundant oxygen-containing functional groups and defect sites, and boron-doped content of 2.96% was successfully prepared. Then, the performance of B-CNTs/PSSF for continuous CWPO of phenol was evaluated. Catalytic results revealed that the B-CNTs/PSSF showed excellent catalytic activity in phenol degradation within 7 h (phenol conversion reached about 100% and total organic carbon (TOC) conversion was up to 68%). In contrast, the average phenol and TOC conversion of CNTs/PSSF were about 75% and 35%, respectively. It indicated that boron doping endowed CNTs with higher catalytic activity.