Abstract Recent advances in electrocatalysts for the CO 2 reduction reaction (CO 2 RR) have led to several promising results, including the large‐scale production of low‐carbon fuels. One of the next steps in this route is the generation of economically and scientifically valuable multicarbon (e.g., C 4 ) chemicals. However, this process has rarely been reported to‐date and has generally suffered from a low production rate ( j partial ≤ 0.097 mA cm −2 ) and Faradaic efficiency (FE) of ≤ 1%. This is largely due to the lack of efficient electrocatalysts for the complicated and interconnected reaction pathway of C 4 generation. Herein, Cu x Ir 1–x alloy nanoparticles (NPs) are shown to convert CO 2 into (CH 3 ) 3 COH ( t ‐BuOH) with a j partial of 0.207 mA cm –2 at a FE of 14.8%, which is the best performance toward C 4 production demonstrated so far. Furthermore, this study proposes a probable mechanism of C 4 formation based on density functional theory (DFT) calculations. The findings suggest that the C 4 production is facilitated by the strong electronic interaction between Cu and Ir and the high oxophilicity of the Ir‐rich surface, which enhances the binding strength of oxygen‐bound intermediates. This work opens the potential of Ir‐based alloys for the CO 2 RR and highlights the production of C 4 chemicals beyond the currently available C 1 –C 3 products.
Compared to Ru single atom catalyst, hetero-RuM (M = Fe, Os, and Ir) double atom catalysts showed improved N 2 RR activity with the help of d xz and d xy bonding orbital, caused by strain, dopant and configurational effects.
Abstract Transition metal phosphides (TMPs) as ever‐evolving electrocatalytic materials have attracted increasing attention in water splitting reactions owing to their cost‐effective, highly active and stable catalytic properties. This work presents a facile synthetic route to NiCoP nanoparticles with Ru dopants which function as highly efficient electrocatalysts for oxygen evolution reaction (OER) in alkaline media. The Ru dopants induced a high content of Ni and Co vacancies in NiCoP nanoparticles, and the more defective Ru doped NiCoP phase than undoped NiCoP ones led to a greater number of catalytically active sites and improved electrical conductivity after undergoing electrochemical activation. The Ru doped NiCoP catalyst exhibited high OER catalytic performance in alkaline media with a low overpotential of 281 mV at 10 mA cm −2 and a Tafel slope of 42.7 mV dec −1 .
Carbon Dioxide Reduction In article number 2300749, Woong Kim and co-workers demonstrate that CuxIr1−x alloy nanoparticles can electrochemically convert CO2 into t-BuOH with a Faradaic efficiency of 14.8%. The study suggests that the strong electronic interaction between Cu and Ir along with the high oxophilicity of the Ir-rich surface can effectively stabilize oxygen-bound intermediates, thereby promoting a productive pathway for multi-carbon production.
Zoning regulations are largely represented by land use, the floor area ratio (FAR), and building coverage ratio (BCR). Changes in the FAR and BCR directly affect the formation of urban space, making it likely that volumes of building space will be regulated. Volume regulation becomes a significant factor influencing the planning of urban space. Also, it is currently being utilized as one of the most powerful means of regulating zoning, which also affects the formation of urban space. This paper analyzes the characteristics of volume regulation and how volume regulation and changes in regulations, are influencing urban space in terms of a unit of land, suggesting several ways for government to use volume regulation as a means of spatial management. To do this, this study uses a vector autoregressive (VAR) model to analyze the effect of volume regulations on urban spatial factors in residential and commercial areas. The fields to be studied are the Seoul area and five individual life zones. The results show that the impacts are differentiated in an each individual zone. Intensity of regulation and degree of influence, used to represent urban density indicators, are found to be oversimplified, necessitating a conceptualization of the classification of volume regulation and use. In addition, the FAR, which is a useful means of controlling urban space, more strongly affects volume.
In this study, we have engineered the MXene supports to boost the single and homo double atoms of Fe, Ru, and Os for the efficient NH3 production via electrochemical nitrogen reduction reaction (N2RR) using DFT calculations. We designed the different MXene surfaces which are composed of nine early transition metals [M2CO2 (M= Cr, Hf, Mo, Nb, Ta, Ti, V, W, Zr)] and examined the activity/stability of single and homo double atoms by calculating the free energy diagram of N2RR, dissolution potential, and agglomeration energy. First, we found that the NH2 adsorption energy is the activity descriptor for representing the NH3 productivity and the density of state near the Fermi level of the single Ru atom is the important factor in determining N2RR activity. Next, our DFT calculation on the descriptor-based computational search for the novel MXene-based catalysts showed that among the chemically and electrochemically stable candidate catalysts, the homo double Ru2/Mo2CO2 catalyst showed the highest NH3 productivity with the high N2RR selectivity over hydrogen evolution reaction. In addition, the best Ru2/Mo2CO2 catalyst exhibited the intermediate density of state near the Fermi level, leading to the optimal descriptor value (NH2 adsorption strength) for NH3 production and in turn the reduction of overpotential for the electrochemical NH3 production. More fundamentally, we identified that the electron density near the Fermi level of these single or double atoms is closely correlated with the electron structure of the cationic metal atoms constituting MXene supports. Our study highlights the rational design of single and homo double atom catalysts by tuning the property of MXene supports, which provides insight on the key factors in enhancing NH3 production at ambient conditions.
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