A Study on the Binary and Ternary CuZnAl Catalysts without Additives for Efficient CO Hydrogenation to Ethanol

Abstract

Synthesis of ethanol from syngas on CuZnAl catalyst without additives has attracted substantial interest. However, the active sites and the reaction mechanism are still not fully understood due to the complexity of the ternary system. Herein, a series of binary (CuZn, CuAl, ZnAl) and ternary CuZnAl catalysts were prepared using complete liquid method for CO hydrogenation to ethanol. The results show that CAT-CZ and CAT-ZA possess much higher ability for ethanol synthesis than CAT-CA, which is attributed to the presence of the key species Zn and the strong interaction at the interface. In situ DRIFTS measurements reveal the intermediate species of each catalyst, indicating that there are different carbon chain growth paths in CAT-CZ and CAT-ZA. The desirable catalytic CO hydrogenation performance (10.87 % of CO conversion and 57.18 % proportion of ethanol in total alcohol) on CAT-CZA can be attributed the existence of multiple mechanisms for the ethanol production process.

Insights into the Inducing Effect of Aluminum on Cu–ZnO Synergy for Methanol Steam Reforming

“…The XPS O 1s spectra of various catalysts are presented in Figure a. After a rigorous deconvolution of the spectra, three peaks can be identified: (1) the peak with the lowest binding energy (530.3 eV, O L ) is ascribed to lattice oxygen of ZnO; (2) the peak at 531.4 eV relates to oxygen species adsorbed on oxygen vacancies (531.4 eV, O V ); (3) the peak with the highest binding energy corresponds to chemisorption oxygen species (532.3 eV, O C ) at the surface, such as carbonate, adsorbed water, or hydroxyl. , The concentration of oxygen vacancies (O v ) can be quantitatively calculated by S Ov /( S OL + S Ov + S Oc ). As shown in Figure a and Table , the densities of surface O v rank in the following order: Cu/ZnO–5Al > Cu/ZnO–3Al > Cu/ZnO–1Al > Cu/ZnO + 3Al > Cu/ZnO.…”

Active Site Synergy of Rh and Co Derived from ZrO2-Supported LaRhxCo1–xO3 Perovskite Nanostructures for the Direct Synthesis of Ethanol from Syngas

“…Syngas, which is produced from natural (shale) gas, carbon dioxide, biomass, coal, and carbon-containing waste, can be used to synthesize ethanol. Therefore, syngas-to-ethanol is one of the green routes using nonpetroleum carbon resources to replace dwindling crude oil sustainably. − Two pathways, namely, indirect synthesis of ethanol (ISE) − and direct synthesis of ethanol (DSE), have been developed for syngas-to-ethanol. − Compared with the ISE process involving multiple catalytic steps, DSE is more promising due to its lower energy consumption and higher transformation efficiency . Although DSE has attracted increasing attention in academic and industrial fields, it has not yet been commercialized …”

“…In the realm of DSE from syngas, many studies have concentrated on a Rh-based catalyst due to its intriguing preferential ethanol selectivity compared with other materials, such as Mo-based, modified Fischer–Tropsch, and methanol synthesis catalysts. − The usual strategies adopted by scientists are the following two aspects: (1) incorporating promoters, such as Fe, Co, Mn, and Li; − (2) adjusting the molar ratio of Rh + and Rh 0 via improving the strong metal–support interaction. − Although some great improvements have been achieved, DSE over a Rh-based catalyst still needs to enhance the ethanol yield and reduce the undesired byproducts simultaneously. Perovskite oxides (ABO 3 ) are often chosen as the catalyst precursor for the DSE reaction with the following remarkable merits: (1) the elements in perovskite oxides are homogeneously distributed at the atomic scale; , (2) the active sites derived from the precursor can deliver higher dispersion due to the strong interaction between the metal and support .…”

CuZnAl@S-1 Catalyst for the Synthesis of Higher Alcohols by CO Hydrogenation

“…The selectivity of ethanol was about 17%, accounting for 57.18% in total alcohol, and the conversion rate of CO was 10.87%. The results showed that the Zn component in the catalyst played an important role, mainly by forming a high activity CuZnO interface site or a CuZn surface alloy . This paper uses an alternate approach to create a CuZnAl catalyst and studies the performance of its CO hydrogenation on a fixed bed reactor to determine whether this outcome is caused by the catalyst manufacturing method and the slurry bed reactor.…”