Search

In this study, finite element software was used to simulate seepage at the core scale, the stress sensitivity of the shale core of the stripe layer and fractures was evaluated, and the production optimization design of reservoir C in block B of the oilfield under different fracturing parameters and wellbore parameters was simulated. The coupled finite element model of reservoir seepage stress was established; the pore elasticity model was used to determine the reservoir deformation; the seepage followed Forchheimer’s law and Darcy’s law; and finally, the liquid production was calculated to optimize the production plan. The results showed that the permeability under the same stress conditions increased nonlinearly with the increase in the striatal angle at the core scale, the permeability under the same effective stress conditions decreased gradually with the increase in the shale/fringe thickness ratio, and the elastic modulus and Poisson’s ratio of the proppant decreased. The permeability stress sensitivity was stronger. In the reservoir-scale model, the production pressure difference was the most significant factor affecting shale oil production, followed by the number of fractures and the length of the horizontal zone wellbore, and the elastic modulus of the proppant and Poisson’s ratio had the least impact on production.

The utilization of fossil fuels has brought unprecedented prosperity and development to human society, but also caused environmental pollution and global warming triggered by excess greenhouse gases emission. For one thing, the excess emission of carbon dioxide (CO2), which has a negative impact on global temperature and ocean acidity, needs to be controlled. For another, the depletion of fossil fuels will eventually force people to seek alternative carbon sources to maintain a sustainable economy. Thus, using renewable energy to convert CO2 and biomass into value-added chemicals and fuels is a promising method to overcome urgent problems. The hydrogenation of CO2 is very important to mitigate the greenhouse effect caused by CO2, while biomass conversion can produce alternative renewable biofuels and green chemicals. As a kind of promising catalyst, heterogeneous single-atom catalyst (SAC) has received extensive attention in the past decades. SACs combine the advantages of homogeneous catalysts with uniform active sites and heterogeneous catalysts that are easily separable. In this review, we will give a comprehensive overview of the latest progress in CO2 selective hydrogenation and biomass conversion via SACs.

Abstract Dopamine is not only a widely used commodity pharmaceutical for treating neurological diseases but also a highly attractive base for advanced carbon materials. Lignin, the waste from the lignocellulosic biomass industry, is the richest source of renewable aromatics on earth. Efficient production of dopamine direct from lignin is a highly desirable target but extremely challenging. Here, we report an innovative strategy for the sustainable production of dopamine hydrochloride from softwood lignin with a mass yield of 6.4 wt.%. Significantly, the solid dopamine hydrochloride is obtained by a simple filtration process in purity of 98.0%, which avoids the tedious separation and purification steps. The approach begins with the acid-catalyzed depolymerization, followed by deprotection, hydrogen-borrowing amination, and hydrolysis of methoxy group, transforming lignin into dopamine hydrochloride. The technical economic analysis predicts that this process is an economically competitive production process. This study fulfills the unexplored potential of dopamine hydrochloride synthesis from lignin.

Abstract Biomass with abundant reproducible carbon resource holds great promise as an intriguing substitute for fossil fuels in the manufacture of high‐value‐added chemicals and fuels. Photocatalytic biomass valorization using inexhaustible solar energy enables to accurately break desired chemical bonds or selectively functionalize particular groups, thus emerging as an extremely creative and low carbon cost strategy for relieving the dilemma of the global energy. Quantum dots (QDs) are an outstandingly dynamic class of semiconductor photocatalysts because of their unique properties, which have achieved significant successes in various photocatalytic applications including biomass valorization. In this review, the current development rational design for QDs photocatalytic biomass valorization effectively is highlighted, focusing on the principles of tuning their particle size, structure, and surface properties, with special emphasis on the effect of the ligands for selectively broken chemical bonds (C─O, C─C) of biomass. Finally, the present issues and possibilities within that exciting field are described.

Abstract Selective conversion of specific functional groups to desired products is highly important but still challenging in industrial catalytic processes. The adsorption state of surface species is the key factor in modulating the conversion of functional groups, which is correspondingly determined by the uniformity of active sites. However, the non‐identical number of metal atoms, geometric shape, and morphology of conventional nanometer‐sized metal particles/clusters normally lead to the non‐uniform active sites with diverse geometric configurations and local coordination environments, which causes the distinct adsorption states of surface species. Hence, it is highly desired to modulate the homogeneity of the active sites so that the catalytic transformations can be better confined to the desired direction. In this review, the construction strategies and characterization techniques of the uniform active sites that are atomically dispersed on various supports are examined. In particular, their unique behavior in boosting the catalytic performance in various chemical transformations is discussed, including selective hydrogenation, selective oxidation, Suzuki coupling, and other catalytic reactions. In addition, the dynamic evolution of the active sites under reaction conditions and the industrial utilization of the single‐atom catalysts are highlighted. Finally, the current challenges and frontiers are identified, and the perspectives on this flourishing field is provided.

Medicinal plant breviscapine is shown to exhibit a protective role in tissue damage after cerebral hemorrhage. The effects of breviscapine on neurological deficit score, brain tissue water content, brain pathological tissue changes, blood-brain barrier bidirectional regulation, and inflammatory factors after cerebral hemorrhage in rats were observed. Western blot and real-time quantitative polymerase chain reaction were performed to explore how Periostin and nuclear factor kappa-B pathway-related factors protein expression contribute to the protective effects of breviscapine on brain injury. Breviscapine inhalation could reduce neurological deficit scores and brain tissue water content. Hematoxylin-eosin staining showed that breviscapine could improve the pathological changes of brain tissue and alleviate brain damage. Breviscapine reduced the abnormal increase of Evans blue content caused by a cerebral hemorrhage, and could significantly inhibit the levels of inflammatory factors interleukin-6 and tumor necrosis factor-α. Also, breviscapine significantly inhibited the expressions of Periostin and nuclear factor kappa-B pathway-related factors after cerebral hemorrhage, and alleviate brain damage by down-regulating Periostin expression and inhibiting nuclear factor kappa-β signaling pathway.

Abstract The chemical transformation of carbon dioxide (CO2) has been considered as a promising strategy to utilize and further upgrade it to value‐added chemicals, aiming at alleviating global warming. In this regard, sustainable driving forces (i.e., electricity and sunlight) have been introduced to convert CO2 into various chemical feedstocks. Electrocatalytic CO2 reduction reaction (CO2RR) can generate carbonaceous molecules (e.g., formate, CO, hydrocarbons, and alcohols) via multiple‐electron transfer. With the assistance of extra light energy, photoelectrocatalysis effectively improve the kinetics of CO2 conversion, which not only decreases the overpotentials for CO2RR but also enhances the lifespan of photo‐induced carriers for the consecutive catalytic process. Recently, rational‐designed catalysts and advanced characterization techniques have emerged in these fields, which make CO2‐to‐chemicals conversion in a clean and highly‐efficient manner. Herein, this review timely and thoroughly discusses the recent advancements in the practical conversion of CO2 through electro‐ and photoelectrocatalytic technologies in the past 5 years. Furthermore, the recent studies of operando analysis and theoretical calculations are highlighted to gain systematic insights into CO2RR. Finally, the challenges and perspectives in the fields of CO2 (photo)electrocatalysis are outlined for their further development.

The excess depletion of carbon‐rich fossil fuels and agroforest biomass resources has aggravated the energy crisis and environmental pollution, causing increased CO2 emissions. Accordingly, the goal of “peak CO2 emissions and carbon neutrality” is proposed to alleviate global warming. CO2‐to‐fuel conversion is considered as a preferable move for reducing the atmospheric CO2 concentration and further upgrading to chemical feedstocks. However, the highly efficient CO2 conversion remains challenging due to the thermodynamic limits and kinetic barriers, which require high energy input through conventional thermocatalysis. Inspired by “artificial photosynthesis,” photocatalytic CO2 transformation has received tremendous attention and makes remarkable progress over the past decades, although it is still far from practical application. Recently, the integrated photothermocatalysis has emerged as an intelligent strategy to utilize solar energy to induce local heating and energetic hot carriers, which synergistically promote CO2‐to‐fuel conversion. The key to the success of CO2 upgradation is catalysts’ development with improved activity, selectivity, and stability. This review highlights the recent advancements in materials designing for practical CO2 conversion through thermocatalysis, photocatalysis, and photothermocatalysis during the past five years, emphasizing the reaction pathways and mechanism on the CO bond activation and intermediates formation. Finally, the current challenges and future opportunities are described.

Developing robust catalysts for alkyne semi-hydrogenation remains a challenge. Here, the authors introduce a scalable protocol to prepare crystal phase and orientation controlled Pd3S nanoparticles supported on carbon nitride, exhibiting unparalleled semi-hydrogenation performance due to a high density of active and selective ensembles.