Catalytic oxidation of volatile organic compounds on Ni-containing catalysts

22 Apr 2021, 15:25
15m
1221 (Lomonosov st. 9)

1221

Lomonosov st. 9

oral Environmental Protection Systems Environmental Protection Systems

Speaker

Prof. Svetlana Tungatarova (D.V. Sokolsky Institute of Fuel, Catalysis and Electrochemistry)

Description

The problem of chemical safety and sanitary air protection is particularly relevant due to the increase of harmful emissions of industrial enterprises, which have a strong toxic effect. Toluene, xylene and ethyl-benzene are major part of the solvents used in various industries, which are present in gaseous emissions. Results of the development of catalysts based on Ni, Cu, and Cr supported on 2 % Ce/θ-Al2O3 with addition of natural clays and waste mixtures of metallurgical production are presented. It was found that the highest degree of toluene conversion (up to 98.8 %) is observed on the three-component Ni-Cu-Cr/2 % Ce/θ-Al2O3 catalyst with optimal metal ratio Ni : Cu : Cr = 1.0 : 3.0 : 0.1 at GHSV = 5×103 h-1 and a temperature of 723 - 773 K. The presence of CeO2 crystals, X-ray amorphous clusters (d = 20 – 100 Å) of variable valence metal oxides NiO and CuO as well as solid metal solutions CuO (NiO) was detected on the surface of optimum catalyst calcined at 873 K using XRD and transition electron microscopy methods. Interaction of oxygen with Ni-Cu-Cr catalyst were studied by temperature-programmed desorption, temperature-programmed reduction and temperature-programmed oxidation methods. It was shown that thermal desorption curve has bends at 773 K and 923 K as well as maximum at 1,023 K, which is caused by desorption of the adsorbed oxygen (670 – 870 K, Edes = 88 - 89 kJ mol-1) and decomposition of Ni and Cu oxides (870 – 1,070 K, Edes = 100 - 128 kJ mol-1) to Cu2O, Ni2O, and then mixed oxides of aluminates (> 1,070 K, Edes = 140 - 144 kJ mol-1), the content of which is sharply reduced when heating at 1,473 K. By IR spectroscopy and thermal desorption has been shown that SO2 chemisorption (a.b. 1165 cm-1, Tmdes = 673 K) and its oxidation to sulfate structures (a.b. 1,235, 1,140, 1,100, 985 and 615 cm-1, Tmdes = 973 K) is the result of reacting a mixture of SO2 + O2 with 9 % Ni-Cu-Cr/2 % Ce/-Al2O3 catalyst at 673 K. These structures are decomposed to SO2 and O2 and destroyed by reduction with hydrogen at T = 973 K.

Acknowledgments
This research was funded by Science Committee of the Ministry of Education and Science of the Republic of Kazakhstan (grant number AP08855562, AP08052090).

Affiliation of speaker D.V. Sokolsky Institute of Fuel, Catalysis and Electrochemistry
Publication IOP Conference Series: Earth and Environmental Science
Position of speaker Prof.

Primary authors

Prof. Svetlana Tungatarova (D.V. Sokolsky Institute of Fuel, Catalysis and Electrochemistry) Dr Zauresh Zheksenbaeva (D.V. Sokolsky Institute of Fuel, Catalysis and Electrochemistry) Dr Tolkyn Baizhumanova (D.V. Sokolsky Institute of Fuel, Catalysis and Electrochemistry) Dr Marzhan Sadenova (D. Serikbayev East Kazakhstan State Technical University) Mrs Rabiga Sarsenova (D.V. Sokolsky Institute of Fuel, Catalysis and Electrochemistry) Prof. Sergey Romanenko (Tomsk Polytechnic University) Mr Sergey Zhevnitskiy (Taraz Regional University named after M.Kh. Dulaty)

Presentation Materials