Lignin, the most abundant aromatic polymer in nature, enables sustainable supply of miscellaneous aromatics as green fuels and chemicals. Obtaining the value-added aromatics from lignin, though subjected to enormous research efforts, mainly relies on depolymerization induced by activated hydrogen species or oxygen species, delivering hydrocarbons and oxygenates. The future bio-refinery demands a broad spectrum of fine chemicals, especially those containing elements other than C, H and O. Heteroatom-containing compounds have emerged as powerful reagents to participate in the bond cleavage in lignin; meanwhile, the obtained heteroatom-containing aromatics, which could be used as dye precursors, pharmaceutical precursors, hydrogen storage materials, etc., extend the application of lignin-derived products...

A mild method of photocatalytic deoxygenation of aromatic ketones to alkyl arenes was developed, which utilized alcohols as green hydrogen donors. No hydrogen evolution during this transformation suggested a mechanism of direct hydrogen transfer from alcohols. Control experiments with additives indicated the role of acid in transfer hydrogenolysis, and catalyst characterization confirmed a larger number of Lewis acidic sites on the optimal Pd/TiO₂ photocatalyst. Hence, a combination of hydrogen transfer sites and acidic sites may be responsible for efficient deoxygenation without additives. The photocatalyst showed reusability and achieved selective reduction in a variety of aromatic ketones.

Column: News Time: 2020-5-22
A special issue on Chinese Journal of Catalysis dedicated to "Advance in Ceria Catalysis" guest-edited by Prof. Feng Wang (DICP) and Dr. Zili Wu (Oak Ridge National Laboratory) becomes online

Column: News Time: 2020-5-10
​Congraduations on Hongji Li for his successful PhD defense on May 10^th, 2020. It's the first virtual PhD defense of our group.

We report the conversion of biomass-derived polyols and sugars into methanol and syngas (CO+H₂) via UV light irradiation under room temperature, and the bio-syngas can be further used for the synthesis of methanol. The cellulose and even raw wood sawdust could be converted into methanol or syngas after hydrogenolysis or hydrolysis pretreatment. We find Cu dispersed on titanium oxide nanorod (TNR) rich in defects is effective for the selective C−C bond cleavage to methanol. Methanol is obtained from glycerol with a co-production of H₂. A syngas with CO selectivity up to 90% in the gas phase is obtained via controlling the energy band structure of Cu/TNR.

Here we demonstrate that photogenerated radicals can be rapidly terminated by surface hydrogen species during photocatalytic decarboxylation of fatty acids on a hydrogen-rich surface that is constructed by the interactions between H₂ and Pt/TiO₂ catalyst, thereby greatly inhibiting oligomerization; C_n–1 alkanes can therefore be obtained from bio-derived C₁₂–C₁₈ fatty acids in high yields (≥90%) under mild conditions (30 °C, H₂ pressure ≤0.2 MPa) and 365 nm light-emitting dode irradiation. Industrial low-value fatty acid mixtures (namely, soybean and tall oil fatty acids) can be transformed into alkane products in high yields (up to 95%). Our research introduces an efficient biomass-upgrading approach that is enabled by subtle control of the radical intermediate conversion on a heterogeneous surface.

Photocatalytic selective oxidation of hydrocarbons to oxygenated chemicals greatly relies on catalytic materials that show high efficiency of photogenerated holes and electrons separation and visible light absorption capacity. We, herein, report one facile calcination approach with ammonium chloride and melamine as the template to synthesize nitrogen-modified Nb₂O₅ nanomeshes material (Nb₂O₅-N), which exhibits a 37-fold reaction rate larger than its commercial counterpart in photocatalytic oxidation of toluene into benzaldehyde under visible light irradiation. The reactivity is ascribed to an extended absorption spectrum within 700 nm by nitrogen modification. In addition, photocurrent response results suggest that a relaxation effect induced by nanomesh structure is beneficial for the separation of charge carriers for enhanced reactivity.

Photocatalytic H₂ evolution from organic feedstocks with simultaneous utilization of photogenerated holes achieves solar energy storage and coproduces value-added chemicals. Here we show visible-light H₂ production from benzyl alcohol (BAL) with controllable generation of deoxybenzoin (DOB) or benzoin (BZ) through tandem redox reactions. Particularly, DOB synthesis circumvents the use of expensive feedstocks and environmentally unfriendly catalysts that are required previously. Under the irradiation of blue LEDs, the key of steering the major product to DOB rather than BZ is to decrease the conduction band bottom potentials of the ZnIn sulfide catalysts by increasing the Zn/In ratio, which results in the dehydration of intermediate hydrobenzoin (HB) to DOB proceeding in a redox-neutral mechanism and consuming an electron–hole pair. As a proof of concept, this method is used to synthesize DOB derivatives in gram scale.