Xi Zhuo Jiang

Carbon dioxide (CO₂) electroreduction using renewable energy provides a sustainable solution to mitigate greenhouse effects and achieve carbon neutrality. Developing high-performance electrocatalysts for the CO₂ reduction reaction (CO₂RR) is key to promoting such a technology. Herein, we systematically explored the CO₂RR catalytic activity of 325 dual-metal-site catalysts (DMSCs) through density functional theory (DFT) calculations. Among them, the Sc/Tc DMSC is particularly advantageous for HCOOH, CH₄, and CH₃CH₂OH production, with limiting potentials of -0.45 V, -0.45 V, and -0.46 V, respectively. The Ti/Rh DMSC can selectively convert CO₂ to CH₃CH₂OH at ultralow overpotentials (U _L = -0.21 V). HCOOH is the preferred product of the CO₂RR on the Mn/Fe site with a U _L of -0.30 V. Mn/Fe presents the highest inhibitory effects on the side reaction, the hydrogen evolution reaction (HER), with a U _L of -0.66 V. Moreover, electronic analysis was conducted to further explain the enhancement for the CO₂RR of explored catalysts at the subatomic level. Our work offers a strategy for screening of high-performance DMSCs and reveals the mechanisms of the CO₂RR to target products for selected catalysts, benefiting the further development of CO₂RR electrocatalysts.

This study conducts a detailed numerical investigation on the spatial distribution of solid obstacles using the large eddy simulation method. It is discovered that although flame acceleration induced by solid obstacles is dominated by factors such as flow field disturbances, vortices and recirculation zones, turbulence, flame surface areas and combustion heat release rates, etc., the characteristics of the leading shock wave are key to detonation initiation. Specifically, the intensity of the leading shock wave, its formation time, and its distance from the flame front significantly affect detonation initiation. Depending on the state of the shock wave, the detonation initiation process may occur through various mechanisms such as shock reflection, shock focusing. Overall, the types of detonation initiation in this study all belong to the shock detonation transition. However, the detonation initiation process can be further classified into two categories: (I) Detonation induced by shock wave reflection; (II) detonation triggered by shock wave focusing. Despite certain disparities in the detonation initiation process, all detonation initiation processes conform to the gradient theory, and the flame evolution processes in all cases consistently follow three stages: the laminar slow-ignition stage; the turbulent deflagration stage; the detonation initiation stage. Furthermore, the study further discerns that, compared to positioning obstacles on the wall, placing obstacles inside the combustion chamber can further augment the detonation-assisting effect. However, excessively sparse or dense spatial distributions of solid obstacles fail to yield the optimal detonation effect. An optimal distribution exists, which triggers the fastest detonation initiation.

Chemical looping combustion (CLC) is a promising and novel technology for carbon dioxide (CO₂) capture with a relatively low energy consumption and cost. CuO, one of the most attractive oxygen carriers (OCs) for carbon dioxide (CO) oxidation, suffers from sintering and agglomeration during the reduction process. Applying an electric field (EF) may promote the CO oxidation process on the CuO surface, which could mitigate sintering and agglomeration by decreasing operating temperatures with negligible combustion efficiency loss. This study performs density functional theory (DFT) simulations to investigate the effects of EF on the oxidation of CO on the CuO (111) surface. The results indicate that both the orientation and strength of the EF can significantly affect the oxidation characteristics of CO on the CuO (111) surface such as total reaction energy, energy barriers of reactions, CO adsorption, and CO₂ desorption. For the first time, this study reveals the role of EF in enhancing CO oxidation through CLC processes via first-principle calculations. Such findings could provide new strategies to improve the performance of CLC processes.

Endothelial cells, located on the surface of blood vessel walls, are constantly stimulated by mechanical forces from the blood flow. The mechanical forces, i.e., fluid shear stress, induced by the blood flow play a pivotal role in controlling multiple physiological processes at the endothelium and in regulating various pathways that maintain homeostasis and vascular function. In this review, research looking at different blood fluid patterns and fluid shear stress in the circulation system is summarized, together with the interactions between the blood flow and the endothelial cells. This review also highlights the flow profile as a response to the configurational changes of the endothelial glycocalyx, which is less revisited in previous reviews. The role of endothelial glycocalyx in maintaining endothelium health and the strategies for the restoration of damaged endothelial glycocalyx are discussed from the perspective of the fluid shear stress. This review provides a new perspective regarding our understanding of the role that blood flow plays in regulating endothelial functionality.

Mechanisms of CO₂ electroreduction to C₁ and C₂ chemicals over catalysts CuNC-4-pyridine and CuCuNC-4a.