Amorphous Boron Dispersed in LaCoO₃ with Large Oxygen Vacancies for Efficient Catalytic Propane Oxidation

Abstract

Unsatisfactory oxygen mobility is a considerable barrier to the development of perovskites for low‐temperature volatile organic compounds (VOCs) oxidation. This work introduced small amounts of dispersed non‐metal boron into the LaCoO3 crystal through an easy sol‐gel method to create more oxygen defects, which are conducive to the catalytic performance of propane (C3H8) oxidation. It reveals that moderate addition of boron successfully induces a high distortion of the LaCoO3 crystal, decreases the perovskite particle size, and produces a large proportion of bulk Co2+ species corresponding to abundant oxygen vacancies. Additionally, surface Co3+ species, as the acid sites, which are active for cleaving the C−H bonds of C3H8 molecules, are enriched. As a result, the LCB‐7 (molar ratio of Co/B=0.93:0.07) displays the best C3H8 oxidation activity. Simultaneously, the above catalyst exhibits superior thermal stability against CO2 and H2O, lasting 200 h. This work provides a new strategy for modifying the catalytic VOCs oxidation performance of perovskites by the regulation of amorphous boron dispersion.

Amorphization of LaCoO3 Perovskite Nanostructures for Efficient Oxygen Evolution

“…31 The enriched O2 in the LaCoO 3 −Reduce not only indicates the abundant oxygen vacancies are introduced into LaCoO 3 during urea reduction process but also provides great potential in accelerating the electrochemical OER, as these active oxygen species are one kind of electrophilic reagent and demonstrate high activity in catalytic oxidation. 36 The OER electrocatalytic activities of the LaCoO 3 −Reduce and LaCoO 3 −Pristine were evaluated by a three-electrode system in 1 M KOH solution. The influences of calcination temperature on the formation of amorphous LaCoO x perovskite and corresponding OER performances are investigated (Figure S5).…”

“…Here, the generated NH 4+ during pyrolysis of urea displaces La 3+ , weakly interacts toward CoO 6 octahedra, and forms N–H–O-Co configuration, and then the removal of N–H results in abundant defects to establish an amorphous structure for LaCoO 3 . The enriched O2 in the LaCoO 3 –Reduce not only indicates the abundant oxygen vacancies are introduced into LaCoO 3 during urea reduction process but also provides great potential in accelerating the electrochemical OER, as these active oxygen species are one kind of electrophilic reagent and demonstrate high activity in catalytic oxidation …”

Perovskite Oxides in Catalytic Combustion of Volatile Organic Compounds: Recent Advances and Future Prospects

“…In another work, non‐metal boron was doped into LaCoO 3 perovskite and their catalytic performance for propane oxidation reaction was investigated. [ 163 ] It revealed that the introduction of boron led to the lattice distortion of LaCoO 3 perovskite, the formation of abundant oxygen vacancies, and enriched surface Co 3+ species, contributing to better reducibility and more active sites. After optimizing the boron doping amount, LaCo 0.93 B 0.07 O 3 (LCB‐7) showed the highest catalytic activity for propane oxidation reaction and superior thermal stability against CO 2 and H 2 O for a test period of 200 h. Taking the high thermal durability into account for practical applications, LCB‐7 should be a promising perovskite‐type catalyst for VOC combustion.…”

Supported RuxIr1‐xO2 Mixed Oxides Catalysts for Propane Combustion: Resistance Against Water Poisoning

“…In the alkane combustion process, water in the reaction feed or produced by the reaction is known to hamper the catalytic combustion reaction, [41–42] a problem that has already been studied extensively for the methane combustion [4,43–46] but to lesser extent for the catalytic propane combustion, employing Pd and Pt‐based catalysts [47–50] . For example, Murata et al.…”

“…In the alkane combustion process, water in the reaction feed or produced by the reaction is known to hamper the catalytic combustion reaction, [41][42] a problem that has already been studied extensively for the methane combustion [4,[43][44][45][46] but to lesser extent for the catalytic propane combustion, employing Pd and Pt-based catalysts. [47][48][49][50] For example, Murata et al 51 found that hydrophobic carrier (α-Al 2 O 3 ) reduces water poisoning in the methane combustion reaction over supported PdO, while Huang et al 52 used water sorbent that was physically mixed with Pd/CeO 2 catalyst to enhance the activity of methane combustion. Since water possibly impedes the catalytic combustion by blocking the active sites, one would expect that water poisoning is equally important in the catalytic propane combustion over Ru x Ir 1-x O 2 -based catalysts and this poisoning effect may depend critically on the composition x of Ru x Ir 1-x O 2 and on the specific carrier material.…”