Precision Chemistry最新文献

Hydrogen energy has garnered significant attention in recent years as a solution to address the global energy crisis and environmental pollution. While water electrolysis stands out as the most promising method to produce green hydrogen, the sluggish reaction kinetics of the oxygen evolution reaction (OER) on the anode increases the cost of hydrogen production. One potential solution to this challenge is replace OER with the thermodynamically more favorable oxidation of small molecules, which can efficiently reduce the energy cost while simultaneously yielding high-value chemicals. Up to now, various organic oxidation reactions have been reported to couple with hydrogen evolution, including alcohol oxidation, biomass platform molecule upgrading, and sacrificial reagents oxidation associated with wastewater treatments. This review concentrates on the recent advancements in the mechanism, catalyst, reactor, and process in this field, with a discussion on its prospects for commercialization.

As a versatile energy carrier, H₂ is considered as one of the most promising sources of clean energy to tackle the current energy crisis and environmental concerns, which can be produced from photocatalytic water splitting. However, solar-driven photocatalytic H₂ production from pure water in the absence of sacrificial reagents remains a great challenge. Herein, we demonstrate that the incorporation of Ru single atoms (SAs) into ZnIn₂S₄ (Ru-ZIS) can enhance the light absorption, reduce the energy barriers for water dissociation, and construct a channel (Ru–S) for separating photogenerated electron–hole pairs, as a result of a significantly enhanced photocatalytic water splitting process. Impressively, the productivity of H₂ reaches 735.2 μmol g^–1 h^–1 under visible light irradiation in the absence of sacrificial agents. The apparent quantum efficiency (AQE) for H₂ evolution reaches 7.5% at 420 nm, with a solar-to-hydrogen (STH) efficiency of 0.58%, which is much higher than the value of natural synthetic plants (∼0.10%). Moreover, Ru-ZIS exhibits steady productivity of H₂ even after exposure to ambient conditions for 330 days. This work provides a unique strategy for constructing charge transfer channels to promote the separation of photogenerated electron–hole pairs, which may motivate the fundamental researches on catalyst design for photocatalysis and beyond.

Microporous molecular crystals are promising materials because of their designable porosity as well as their resistance to chemical and other stimuli. Here, we developed microporous molecular cocrystals by taking advantage of the specific interactions between porphyrins and fullerene molecules. Single-crystal X-ray diffraction analysis revealed that one nickel(II) porphyrin interacts with two fullerene molecules to form a two-dimensional honeycomb network with an eclipsed stacking mode, providing one-dimensional void channels. After the pores were activated by heat treatment or mechanical grinding, the prepared cocrystal can incorporate gas and solvent molecules reversibly while maintaining its single-crystallinity. Also, it retained its single-crystallinity in the presence of water, acid–base, or high pressure. These findings in this study expand the availability of molecular crystals based on intermolecular interactions as porous materials, which are expected to work under conditions that have not been applicable to other molecule-based porous materials.

Lignin, as the second largest renewable biomass resource in nature, has increasingly received significant interest for its potential to be transformed into valuable chemicals, potentially contributing to carbon neutrality. Among different approaches, renewable electricity-driven biomass conversion holds great promise to substitute a petroleum resource-driven one, owing to its characteristics of environmental friendliness, high energy efficiency, and tunable reactivity. The challenges lie on the polymeric structure and complex functional groups in lignin, requiring the development of efficient electrocatalysts for lignin valorization with enhanced activity and selectivity toward targeted chemicals. In this Review, we focus on the advancement of electrocatalytic valorization of lignin, from monomers, to dimers and to raw lignin, toward various value-added chemicals, with emphasis on catalyst design, reaction innovation, and mechanistic study. The general strategies for catalyst design are also summarized, offering insights into enhancing the activity and selectivity. Finally, challenges and perspectives for the electrocatalytic conversion of lignin are proposed.

The inert gold substrate is one of the most commonly used substrates for synthesizing transition metal dichalcogenides (TMDCs), while the growth mechanism of TMDCs on gold substrates in a sulfur-rich environment is still unclear. Based on density functional theory calculations, we explored the reconstruction of the gold surface in a sulfur-rich environment, which is one of the conditions for the growth of TMDCs. We clearly revealed that both Au(100) and Au(111) surfaces tend to form metal sulfide buffer layers between TMDCs and the metallic substrate, which are the square pattern of Au4S4 on Au(100) surface and the hexagonal pattern of Au6S6 on Au(111) surface, respectively. In the sulfur-rich environment, both square and hexagonal patterns are energetically highly stable, greatly weakening the interaction between TMDCs and the substrate. Interestingly, both buffer layers inherit the symmetry of the substrate and thus have no significant effect on the growth behavior of TMDCs. This study explains many experimental puzzles and elucidates the growth behavior of 2D materials on various substrates.