Synthesis of Cu/diatomite composite and its catalytic activity via phenol oxidation in aqueous solutions

Abstract

In this paper, Cu/diatomite composites were synthesised by dispersing copper ions onto the diatomite surface via the hydrolysis reaction of copper(II) nitrate trihydrate salt in water. The effects of reaction temperature and time on the catalytic activity of the obtained composite were investigated. The material was characterised by using energy-dispersive X-ray spectroscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and nitrogen adsorption-desorption isotherms. Under optimal conditions, the obtained Cu/diatomite composite with a specific surface area of 44.7 m²/g contained about 0.91% Cu (wt.%), highly dispersed on ​​the diatomite matrix. The decomposition reaction of phenol in an aqueous solution with hydrogen peroxide was used to evaluate the catalytic activity of the material. Phenol conversion was 94% under the following conditions: reaction time 240 min, temperature 50 °C, phenol concentration 1000 mg/L, Cu/diatomite 1 g/L, hydrogen peroxide 6.6 g/L, and neutral pH. The durability and reusability of the catalytic materials were also assessed.