resumo
This paper presents the results of an investigation of three (Cu/La-Si and Cu/Zr-Si) and four (Cu/La-Zr-Si) component oxide systems in aqueous ethanol conversion into 1,3-butadiene, with special accent to the effect of lanthanum in the catalyst composition. The catalysts were characterized by HRTEM, SEM, DR UV-vis, in situ near ambient pressure X-ray photoelectron spectroscopy (NAP-XPS), FTIR with pyridine, and TPD-CO2. The high (>= 65%) 1,3-butadiene selectivity is achieved during the conversion of both rectified and aqueous ethanol over the studied catalysts. Catalyst activity of the four-component oxide systems depends on an introduction order of the components, which determines acid-base characteristics of the surface. A modification of the Cu/Zr-Si catalyst with lanthanum increases their activity in aqueous ethanol conversion into 1,3-butadiene. The positive effect of lanthanum addition into Cu/Zr-Si catalyst can be explained by the formation of lanthanum containing base sites like [La-(O)double over dot-Si] and [La-(O)double over dot-H] being tolerant to the action of water. The differences in the interaction of reaction intermediates with surface Zr-and La-containing sites are found out by C 1 s NAP-XPS measurements, and the effect of H2O on adsorption of carbon coke, ethoxy species and acetaldehyde over the catalyst surface is shown.
palavras-chave
AMBIENT-PRESSURE XPS; SIO2 SUPPORT; IN-SITU; BUTADIENE; ACID; ETHANOL/ACETALDEHYDE; PERFORMANCE; ZN; TEMPERATURE; ADSORPTION
categoria
Chemistry
autores
Kyriienko, PI; Larina, OV; Balakin, DY; Vorokhta, M; Khalakhan, I; Sergiienko, SA; Soloviev, SO; Orlyk, SM
nossos autores
Sergii Sergiienko
Investigador Júnioragradecimentos
This work was financially supported by the National Academy of Sciences of Ukraine, program KPKVK 6541230 Support for the development of priority areas of scientific research (0120U101212). The authors also acknowledge CERIC-ERIC Consortium for access to experimental facilities at FESEM and NAP-XPS at the Charles University in Prague (Proposal number: 20172060) and financial support.