Heterostructured Electrocatalysts for Hydrogen Evolution Reaction Under Alkaline Conditions

The hydrogen evolution reaction(HER) is a half-cell reaction in water electrolysis for producing hydrogen gas. In industrial water electrolysis, the HER is often conducted in alkaline media to achieve higher stability of the electrode materials. However, the kinetics of the HER in alkaline medium is slow relative to that in acid because of the low concentration of protons in the former.Under the latter conditions, the entire HER process will require additional effort to obtain protons by water dissociation near or on the catalyst surface. Heterostructured catalysts, with fascinating synergistic effects derived from their heterogeneous interfaces, can provide multiple functional sites for the overall reaction process. At present, the activity of the most active known heterostructured catalysts surpasses(platinum-based heterostructures) or approaches (noble-metal-free heterostructures) that of the commercial Pt/C catalyst under alkaline conditions, demonstrating an infusive potential to break through the bottlenecks. This review summarizes the most representative and recent heterostructured HER catalysts for alkaline medium. The basics and principles of the HER under alkaline conditions are first introduced, followed by a discussion of the latest advances in heterostructured catalysts with/without noblemetal-based heterostructures. Special focus is placed on approaches for enhancing the reaction rate by accelerating the Volmer step. This review aims to provide an overview of the current developments in alkaline HER catalysts, as well as the design principles for the future development of heterostructured nano-or micro-sized electrocatalysts.

Highly selective and efficient electroreduction of CO_(2) in water by quaterpyridine derivative‐based molecular catalyst noncovalently tethered to carbon nanotubes

A disubstituted quaterpyridine based cobalt complex non‐covalently tethered to multiwalled carbon nanotube(MWCNT)substrate,forming a hybrid catalyst,Co‐qpyCOOH/CNT,catalyzed the conversion of CO_(2) to CO under aqueous conditions.At an optimal and uniform loading,it exhibited remarkable catalytic activity,near‐exclusive selectivity,and high stability towards the formation of CO.At a mere cathodic potential of−0.65 V versus RHE(η=0.54 V),it achieved a high partial current density of−6.7 mA/cm^(2) and a F.E.CO=100%.In addition,with 20 h of stable operation,hydrogen evolution remained practically undetected.Its hybrid structure due to noncovalent immobilization on MWCNT imparted the intrinsic activity and much‐needed stability in performance whereas‒COOH groups may stabilize the intermediates by acting as H‐bond donors,promoting catalytic activity.Tethering to a conductive solid substrate and tuning of the second sphere of coordination played an important role in its performance to achieve desired reduction product with high selectivity and activity.

Bimetallic MOF derived nickel nanoclusters supported by nitrogendoped carbon for efficient electrocatalytic CO_(2)reduction

Utilizing electrocatalytic CO_(2)reduction(ECR)to decrease the carbon footprint has been regarded as a promising pathway.Herein,we report the synthesis of Ni nanoclusters(NCs)of below 2 nm highly dispersed on N-doped carbon using a Ni/Zn bimetallic metal-organic framework(MOF)precursor.The size and the content of the Ni catalyst can be effectively controlled by varying the Ni:Zn ratio in MOF precursors.The-NH2 group in MOF ligand critically influences the size of Ni catalyst,as well as the property of the carbon substrate.At the optimum ratio of 1:150,Ni NCs with an average size of 1.9 nm anchored on pyridinic N-rich carbon were obtained after MOF pyrolysis.The resultant catalyst exhibits a high Faradaic efficiency for CO(FECO,98.7%)and considerable partial current density for CO(JCO,−40.4 mA·cm^(−2))at−0.88 V versus reversible hydrogen electrode(RHE).Benefiting from the synergistic effect of small Ni clusters and their optimal interaction with the carbon support,the catalyst displays exceptional long-term stability.Density functional theory(DFT)calculations carried out for the three model structures confirm that Ni NCs anchored on N-doped carbon facilitate the easier formation of*COOH intermediate and faster electron transfer rate compared with the large-sized Ni particles represented by Ni(111)and the N-doped carbon without Ni.

OntoPowSys: A power system ontology for cross domain interactions in an eco industrial park

Knowledge management in multi-domain,heterogeneous industrial networks like an Eco-Industrial Park(EIP)is a challenging task.In this paper,an ontology-based management system has been proposed for addressing this challenge.It focuses on the power systems domain and provides a framework for integrating this knowledge with the other domains of an EIP.The proposed ontology,OntoPowSys is expressed using a Description Logics(DL)syntax and the OWL2 language was used to make it alive.It is then used as a part of the Knowledge Management System(KMS)in a virtual EIP called the J-Park Simulator(JPS).The advantages of the proposed approach are demonstrated by conducting two case studies on the JPS.The first case study illustrates the application of optimal power flow(OPF)in the electrical network of the JPS.The second case study plays an important role in under-standing the cross-domain interactions between the chemical and electrical engineering domains in a bio-diesel plant of the JPS.These case studies are available as web services on the JPS website.The results showcase the advantages of using ontologies in the development of decision support tools.These tools are capable of taking into account contextual information on top of data during their decision-making processes.They are also able to exchange knowledge across different domains without the need for a communication interface.

Semantic 3D City Agents- An intelligent automation for dynamic geospatial knowledge graphs

This paper presents a system of autonomous intelligent software agents,based on a cognitive architecture,capable of automated instantiation,visualisation and analysis of multifaceted City Information Models in dynamic geospatial knowledge graphs.Design of JPS Agent Framework and Routed Knowledge Graph Access components was required in order to provide backbone infrastructure for an intelligent agent system as well as technology agnostic knowledge graph access enabling automation of multi-domain data interoperability.Development of CityImportAgent,CityExportAgent and DistanceAgent showcased intelligent automation capa-bilities of the Cities Knowledge Graph.The agents successfully created a semantic model of Berlin in LOD 2,compliant with CityGML 2.0 standard and consisting of 419909661 triples described using OntoCityGML.The system of agents also visualised and analysed the model by autonomously tracking interactions with a web interface as well as enriched the model by adding new information to the knowledge graph.This way it was possible to design a geospatial information system able to meet demands imposed by the Industry 4.0 and link it with the other multi-domain knowledge representations of The World Avatar.

Optimal Placement of Phasor Measurement Unit in Smart Grids Considering Multiple Constraints

The distribution of measurement noise is usually assumed to be Gaussian in the optimal phasor measurement unit(PMU)placement(OPP)problem.However,this is not always accurate in practice.This paper proposes a new OPP method for smart grids in which the effects of conventional measurements,limited channels of PMUs,zero-injection buses(ZIBs),single PMU loss contingency,state estimation error(SEE),and the maximum SEE variance(MSEEV)are considered.The SEE and MSEEV are both obtained using a robust t-distribution maximum likelihood estimator(MLE)because t-distribution is more flexible for modeling both Gaussian and non-Gaussian noises.The A-and G-optimal experimental criteria are utilized to form the SEE and MSEEV constraints.This allows the optimization problem to be converted into a linear objective function subject to linear matrix inequality observability constraints.The performance of the proposed OPP method is verified by the simulations of the IEEE 14-bus,30-bus,and 118-bus systems as well as the 211-bus practical distribution system in China.

Semantic 3D City Database—An enabler for a dynamic geospatial knowledge graph

This paper presents a dynamic geospatial knowledge graph as part of The World Avatar project,with an underlying ontology based on CityGML 2.0 for three-dimensional geometrical city objects.We comprehensively evaluated,repaired and refined an existing CityGML ontology to produce an improved version that could pass the necessary tests and complete unit test development.A corresponding data transformation tool,originally designed to work alongside CityGML,was extended.This allowed for the transformation of original data into a form of semantic triples.We compared various scalable technologies for this semantic data storage and chose Blazegraph™as it provided the required geospatial search functionality.We also evaluated scalable hardware data solutions and file systems using the publicly available CityGML 2.0 data of Charlottenburg in Berlin,Germany as a working example.The structural isomorphism of the CityGML schemas and the OntoCityGML Tbox allowed the data to be transformed without loss of information.Efficient geospatial search algorithms allowed us to retrieve building data from any point in a city using coordinates.The use of named graphs and namespaces for data partitioning ensured the system performance stayed well below its capacity limits.This was achieved by evaluating scalable and dedicated data storage hardware capable of hosting expansible file systems,which strengthened the architectural foundations of the target system.

过渡金属氧化物析氧催化都是通过氧氢氧化物实现的吗?（英文）

本文首先简单回顾了电解水的发展历史以及碱性和酸性条件下电解水的电极材料特点.对于碱性条件下的电解水,电极材料以过渡金属氧化物为主.近年来,人们对于过渡金属氧化物的析氧反应开展了大量的研究,特别关注钙钛矿、尖晶石、氧氢氧化物等催化剂.析氧反应条件苛刻,一些氧化物催化剂会发生表面重构,转化为过渡金属氧氢氧化物.因此,对这些氧化物来讲,真正的催化剂表面是一个氧氢氧化物的表面.另一方面,一些氧化物在析氧反应中表现出较强的稳定性,一般认为这些氧化物的表面不会发生重构,因而没有氧氢氧化物的生成.一些已知的基于氧化物结构的活性描述参数也对该观点提供了实验和理论支持.最后,本文提出尚待回答的一个问题:在析氧反应中是否所有的过渡金属氧化物都会发生表面重构而生成一个氧氢氧化物的表面?不管以上问题的答案是什么,该如何设计预催化剂实现重构后的高活性表面将成为未来关注的热点之一.