Study of Ce, Ca, Fe, and Mn-Doped LaCoO3 Perovskite Oxide for the Four-Way Purification of PM, NOx, CO, and HC from Diesel Engine Exhaust

Abstract

Perovskite-type catalysts were widely used in the field of automobile exhaust purification due to their inherent physicochemical properties and excellent doping characteristics. A series of La1-xMxCo1-yNyO3 (M=Ce, Ca; N=Fe, Mn) perovskite-type catalyst samples were prepared by sol-gel method for the four-way purification of PM, NOx, CO, and HC emitted by diesel exhaust. The activity of catalyst samples was tested by simulation experiments and hydrogen temperature-programmed reduction (H2-TPR). Catalyst samples were characterized by means of XRD, FT-IR, SEM, BET, and XPS analysis. The results demonstrated that the perovskite-type catalyst samples with a particle pore size of 3–5 μm can be prepared by sol-gel method. When A-site of LaCoO3 perovskite-type oxide was doped by cerium ions, the catalyst samples produced small distortion. The doping of cerium ions to A-site was more conducive to the four-way purification of diesel exhaust than calcium ions. La0.8Ce0.2CoO3 perovskite-type samples showed the best purification efficiency, and the purification efficiencies of PM, NOx, CO, and HC were 90%, 85%, 94%, and 100%, respectively. When the B-site of La0.8Ce0.2CoO3 perovskite was doped with iron ions, the purification efficiency of catalyst samples for PM and NOx can be further enhanced. When the B-site of La0.8Ce0.2CoO3 perovskite was doped with manganese ions, the purification efficiency of the catalyst samples for PM can be further enhanced. It can be seen from the simulation experiments that La0.8Ce0.2Co0.7Fe0.3O3 perovskite was the best doping amount, and the purification efficiencies of PM, NOx, CO, and HC were 95%, 92%, 94%, and 100%, respectively.

Effect of B-Site Element on the Structure and Catalytic Performance for Toluene of the 3DOM CeBO3 Catalyst

“…Cerium oxide is an excellent catalyst with abundant oxygen vacancies and strong interactions with other metals, so it is expected to be a promising substitute for the conventional lanthanum-based perovskite. Wu and Wang found that the catalysts prepared by partially replacing La with Ce increased the oxygen vacancy concentration of the catalyst, which also showed a large amount of α-O (adsorbed oxygen) desorption in O 2 -TPD characterization. The O ads /O latt ratio was also higher than that of the undoped or doped catalysts with other metal elements, which created conditions for good catalytic performance.…”

Preparation of biomorphic porous La0.8Ce0.2Fe0.3Co0.7O3 perovskite‐type catalysts for automobile exhaust purification

“…26 Our previous studies showed that La 0.8 Ce 0.2 Fe 0.3 Co 0.7 O 3 can achieve the four-way purification of PM, NO x , CO and HC emitted by automobile exhausts, and the purification efficiency are 95%, 92%, 100%, and 94%, respectively. 27 In this work, biomorphic porous La 0.8 Ce 0.2 Fe 0.3 Co 0.7 O 3 perovskite-type catalysts were prepared by a facile bio-templating method taking wood fiber as template for achieving the four-way purification of PM, NO x , CO, and HC emitted by automobile exhausts.…”

“…Ming Zhou et al prepared biomorphic porous zinc oxide with wood fiber as template, which proved the specie of wood template and sintering temperature played vital roles in the pore size distribution, specific surface area, and pore volume of the product 26 . Our previous studies showed that La 0.8 Ce 0.2 Fe 0.3 Co 0.7 O 3 can achieve the four‐way purification of PM, NO x , CO and HC emitted by automobile exhausts, and the purification efficiency are 95%, 92%, 100%, and 94%, respectively 27 …”

Effect of Redox Additive in Aqueous Electrolyte for Electrochemical Energy Storage Applications of A and B Site Ordered LaCaCoCrO6 Double Perovskite

“…[32] In addition, calcium is abundant and inexpensive, and its combination with transition metals such as Cr and Co, which have variable valences, can lead to effective physicochemical properties such as redox performance, oxygen mobility, ionic conductivity, etc. [33] The electrochemical performance of LaCaCoCrO 6 double perovskite has been compared with other double perovskites in Table 1. [34][35][36][37] In addition to the material used for the electrode, the electrolyte is critically important for electrochemical analysis.…”