A combined experimental and DFT study of active structures and self-cycle mechanisms of mononuclear tungsten peroxo complexes in oxidation reactions

Chemical defects and hydroxyls tailored porous tungsten-iron-lanthanum solid solution surface frustrated Lewis pairs for boosting visible-light photothermal oxidation of cyclohexane

Photothermal synergy catalysis for cyclohexane oxidation is recognized as an effective and environmentally friendly strategy for producing a mixture of cyclohexanone and cyclohexanol (known as KA oil). However, certain challenges hinder its application for the one-step production of adipic acid (AA), highlighting the need for further advancements. This study presents a successful strategy for preparing a porous coral-shaped tungsten-iron-lanthanum solid solution (L-WFe5La5Ox-450) through a combination of cold gelation and calcination methods. The surface frustrated Lewis pairs (FLPs) of the L-WFe5La5Ox-450 solid solution were tailored by the abundant chemical oxygen defects and hydroxyls formed during the preparation process. The L-WFe5La5Ox-450 solid solution demonstrated exceptional catalytic performance for the one-step production of AA via solvent-free photothermal oxidation of cyclohexane under visible-light conditions. It achieved a remarkable cyclohexane conversion of 12.5 % with a selectivity of 98.0 % to the desired products (40.3 % and 57.7 % selectivities for the liquid product KA oil and solid product AA, respectively). Compared to S-WFeLaOx-450 prepared by conventional solvothermal methods, the L-WFe5La5Ox-450 solid solution exhibited 2.4- and 2.9-folds higher cyclohexane conversion and AA selectivity, respectively, for photothermal catalytic oxidation. Density functional theory computations and in situ experimental findings clarified the mechanism through which the FLPs on the surface of L-WFe5La5Ox-450 enhance photothermal cyclohexane oxidation. Overall, the involved meticulous design provides insights into the fabrication of porous tungsten-based solid solutions and promotes the customization of surface FLP sites for efficient photothermal synergy oxidation.

Catalyst and reactor design considerations for selective production of acids by oxidative cleavage of alkenes and unsaturated fatty acids with H2O2

Mechanistic insight and measurements of apparent kinetics for productive and non-productive reaction pathways guide the development of semi-batch reactors and conditions for stable production of carboxylic acids and diacids over supported tungstate catalysts.

Recent application of calculations of metal complexes based on density functional theory

Recent application of density functional theory (DFT) for metal complexes is reviewed to show the achievements of DFT and the challenges for it, as well as the methods for selecting proper functionals.