Heterogeneously catalyzed liquid oxidation of olefins with O₂ provides an alternative way for synthesizing high-value added chemicals. Herein, we report a straightforward urea-redox and sol-gel process for synthesizing LaCo_xCu_1−xO₃ for aerobic photo-oxidation of cyclohexene. Our research highlights a marked increase in the proportions of Co²⁺ and Cu⁺ species in a low chemical state, as well as enhanced visible light absorption through this method. Mechanistic investigations suggest that the catalytic process, particularly with LaCo_0.7Cu_0.3O₃, involves a radical pathway mediated by reactive oxygen species. The presence of Cu⁺/Co²⁺ species and surface oxygen vacancies is proposed to boost O₂ adsorption and activation on the catalyst, facilitating the formation of 2-cyclohexene-1-hydroperoxides. Furthermore, Cu²⁺/Co³⁺ species are thought to aid in generating cyclohexene-derived radical species. The efficient aerobic oxidation of cyclohexene on LaCo_0.7Cu_0.3O₃ catalyst relies on the formation of reactive oxygen species and carbon radicals, facilitated by its strong visible light illumination. It achieves a cyclohexene conversion of 89.4% and selectivity to cyclohex-2-ene-1-one of 72.2%, along with stable recyclability after six reuses. The creation of nano-structured LaCo_xCu_1−xO₃ through the urea-redox and sol-gel process offers a promising avenue for the development of highly efficient catalysts for the aerobic photo-oxidation of cyclohexene to cyclohex-2-ene-1-one in the future.

In this study, a novel non-metallic carbon-based catalyst co-doped with boron and nitrogen (B,N) was successfully synthesized. By precisely controlling the carbonization temperature of a binary mixed ionic liquid, we selectively modified the doping site structure, ultimately constructing a B,N co-doped frustrated Lewis acid-base pair catalyst. This catalyst exhibited remarkable catalytic activity, selectivity, and stability in the dehydrochlorination reaction of 1,1,2-trichloroethane (TCE). Detailed characterization and theoretical calculations revealed that the primary active center of this catalyst was the BN₃ configuration. Compared to conventional graphitic N structures, the BN₃ structure had a higher p-band center, ensuring superior adsorption and activation capabilities for TCE during the reaction. Within the BN₃ site, three negatively charged nitrogen atoms acted as Lewis bases, while positively charged boron atoms acted as Lewis acids. This synergistic interaction facilitated the specific dissociation of chlorine and hydrogen atoms from TCE, significantly enhancing the 1,1-dichloroethene selectivity. Through this research, we not only explored the active site structure and catalytic mechanism of B,N co-doped catalysts in depth but also provided an efficient, selective, and stable catalyst for the dehydrochlorination of TCE, contributing significantly to the development of non-metallic catalysts.

Oxidative couplings of aliphatic alkynes are crucial for the production of naturally occurring 1,3-diynes. Herein we report the novel approach for effective synthesis of unsaturated coordinated N doped copper oxides (N-CuO_x) catalyst, and uncover that N-CuO_x catalyst as an additive-free and cost-effective heterogeneous catalyst has highly catalytic performance for directly oxidative coupling of aliphatic alkynes. The key to achieve efficient oxidative coupling of aliphatic alkynes is the synergistic effect of N species and uncoordinated O/Cu species caused by N dopants, which undergoes the Langmuir–Hinshelwood reaction mechanism. The N-CuO_x catalyst displays ~ 89.1% yield for hexadeca-7,9-diyne under mild conditions and stable reusability (5 cycles), showing significant advances compared with the traditionally copper oxides. These findings highlight the heteroatom dopants that provide a new methodology for designing efficient copper catalysts in synthesis of naturally occurring 1,3-diynes.

Rational design of earth-abundant transition metal oxides catalysts is highly desirable for developing sustainable chemical processes. Herein, we demonstrate a prospective interstitial nitrogen engineering for fabricating oxygen vacancies (OVs)-rich nitrogen-doped-Mn_xCo_3-xO₄ (N-Mn_xCo_3-xO₄) oxide catalyst, in which the ratio of OVs concentration of N-Mn_xCo_3-xO₄ to Mn species is as high as 1:1, according to the characterizations of X-ray absorption (XAS) and X-ray photoelectron (XPS) spectroscopies. The promising strategy of interstitial nitrogen engineering through lattice distortion caused by the Jahn-Teller effect can significantly increase the amount of interstitial nitrogen. The resulting catalyst enables an additive-free aerobic dehydrogenation coupling of aromatic amine to afford azo compounds with > 99% yield and > 99% selectivity at 60 °C. We observed the superb catalytic activity is promoted by the enhanced oxygen mobility in OVs, which were created by the interstitial nitrogen in the catalyst matrix. The presence of interstitial nitrogen in transition metal oxides in this study shows how the manipulation of catalyst matrix can increase the OV sites to promote aerobic oxidation reaction.