Structure and catalytic activity of MoZnAlO catalyst for degradation of cationic red GTL under room conditions

A series of MoZnAlO catalysts with different Zn/Al molar ratios were prepared. The structure of the catalysts was characterized using ICP-OES, zeta potential, XRD, BET, FTIR, H2-TPR, O2-TPD and ESR. The catalytic activity of these catalysts on the degradation of cationic red GTL wastewater under room condition was investigated. The experimental results showed that the highest color removal efficiency and TOC removal efficiency of cationic red GTL can reach 90.9% and 65.8% by the MoZnAlO catalyst with 1:1 of Zn/Al molar ratio respectively. Associated with the characterization results of these catalysts, MoZnAlO catalyst with 1:1 of Zn/Al molar ratio with highest catalytic activity could be contributed to its lowest zeta potential, largest specific surface area, special crystalline phases, special Mo valences, largest number of active adsorption sites and the maximum active species of 1O2 or OH. The stable of these catalysts was also studied. Due to the lower leaching concentrations of Zn, Mo and Al, MoZnAlO catalyst with Zn/Al molar ratio from 1:1 to 1:3 has a good stability. It is thought that Al3+ plays a more important part in determining the distance between metals, thus it affects the leaching of metals.

► Structure–activity relationship in MoZnAlO catalyst was studied.
► Zn/Al molar ratio had an effect on catalytic activity of the catalyst.
► Structural characteristics, morphological information of these catalysts were discussed.
► The catalyst with 1:1 of Zn/Al showed the best catalytic activity and lower metal leaching.