二氧化碳与氢合成甲醇技术和产业化进展

  目的  二氧化碳和氢合成甲醇是实现二氧化碳大规模利用的重要途径之一，对CCUS产业链条的发展具有的重要支撑作用。  方法  文章主要对二氧化碳加氢制甲醇热力学特性、催化剂开发、产业化发展和技术经济性情况进行了综述。  结果  Cu基催化剂、贵金属催化剂和In₂O₃催化剂是主要反应催化剂类型，具有较好的催化性能，但仍有待进一步提高以满足高二氧化碳转化率和高甲醇选择性。尽管二氧化碳加氢制甲醇技术进步很快，目前已处于中试试验示范阶段，但受限于氢气原料成本较高和当前甲醇价格较低当前还难以大规模推广。  结论  随着氢能产业发展带来氢气价格的下降以及未来全国碳交易市场的启动，二氧化碳加氢制取甲醇将迎来新的发展。     

新能源制氢在传统炼化企业的应用

  目的  化石燃料和新能源电力在使用和发展中面临着问题与挑战。为解决传统炼化企业依赖化石燃料制氢中的碳排放问题,和新能源电力发展中的波动性问题提供建议,有必要对氢气制备技术的应用与发展,和传统炼化企业的氢气网络状况进行梳理。  方法  调研了氢气制备技术的应用与发展,尤其关注了关键技术电解水制氢技术的应用发展;分氢制备、氢使用、氢纯化三部分对传统炼化企业的氢气网络进行了深入剖析。  结果  通过总结,提出通过电解水制氢技术将富余的新能源电力与传统炼化企业氢网络相结合的设想。在传统炼化企业附近布置新能源电给,不但可以供炼厂日常用电,还可将因波动性大而无法直接利用的弃电部分,直接通过电解水制氢技术,制氢供传统炼化企业使用,有效降低传统炼化企业的碳排放强度。  结论  要解决化石燃料使用中的碳排放问题与新能源电力使用中波动性高的问题,实现新能源制氢在传统炼化企业的应用,还面临着诸多挑战。     

共价有机框架材料(COFs)在氧电极电催化中的研究进展

在碳达峰、碳中和的目标之下,燃料电池、金属-空气电池、电解水等清洁能源技术提高了能源利用率,在未来将成为新的能源消费方式.氧还原反应(ORR)、氧析出反应(OER)因其缓慢的动力学过程而导致此类清洁能源技术的发展受到阻碍.贵金属催化剂虽被认为是最高效的催化剂,但其成本高、稳定性低,寻找非贵金属催化剂已成为相关研究的趋势.共价有机框架材料(COFs)作为一类新兴的材料,由有机单体通过特殊的共价键连接而成,因其具有可调控的结构、低密度、高稳定性、较大比表面积等独特的优点,通过合理的设计策略,将其应用于电催化剂的研究在近年来逐步兴起.本文回顾了近期适用于ORR、OER及ORR/OER双功能电催化的二维COFs(2D COFs)材料,主要介绍了以纯COFs作为电催化剂、COFs与其他材料形成复合结构、COFs热解碳化等策略制备高效电催化剂,并从分子设计及电子调控等层面上梳理了上述策略对电催化活性中心的形成或电催化活性提升的原因,对当前存在的问题提出总结,以期在今后的研究中起到一定借鉴意义.     

碱性水电解非贵金属析氧催化剂的研究进展

"绿氢"能源的大规模应用依赖于电解水技术。和析氢反应(HER)相比,析氧反应(OER)是水电解过程中的关键反应,其动力学反应缓慢。目前,非贵金属OER电催化剂的活性和稳定性不佳,深入OER过程机理的理解和催化剂活性方面的研究有助于OER速率的提升。文章综述了近年来在碱性体系中对水电解制氢非贵金属析氧催化剂的研究讨论、分析和总结,主要从材料掺杂类、形貌调控类、调节电子结构类和复合结构类4个方面来阐述。     

电解水制氢在电厂和氢能项目的设计应用

  目的  电解水制氢技术已普遍应用于燃煤电厂、燃气电厂和核电厂，也将更多地应用于可再生能源发电厂配套的氢能项目，有必要对制氢系统设计方案进行探讨。  方法  以某燃煤电厂和风力发电及太阳光伏发电厂配套氢能项目为例，依据相关标准规范的设计规定，阐述了相应的电解水制氢系统设计方案。  结果  碱性电解水制氢技术成熟、安全可靠，能为电厂氢冷发电机、加氢站和氢气用户持续提供满足纯度、湿度要求的氢气。  结论  文章旨在为更多电厂和氢能项目电解水制氢系统的设计提供可参考的方案。     

氢能产业链及氢能发电利用技术现状及展望

  目的  随着“碳达峰、碳中和”目标的提出和能源改革的日益深入,氢能作为重要的工业原料和能源燃料在近年来得到广泛关注并进入快速发展时期。氢能产业链主要包含氢气的制备、储存、运输、利用等环节,涉及众多产业交叉融合与技术创新,文章旨在梳理氢能产业链现状并分析各节点面临的挑战,为今后的氢能产业发展提供建议。  方法  对现有氢能产业链各节点涉及的技术现状开展调研,分析其面临的问题与挑战,并提出相应建议。  结果  研究发现:虽然我国在氢能产业所涉及的各方面均有一定技术储备及产业布局,但仍然面临较多的技术短板有待突破。其中,碱性电解水技术、高压储氢技术、天然气管道掺氢输送技术等已经初步具备应用条件,适合开展示范项目。而低温液氢技术、质子交换膜制氢和燃料电池技术、固体氧化物制氢和燃料电池技术仍存在部分难题,有待进一步突破。同时,我国的掺氢燃机发展较为落后,与国际先进水平存在较大差异。  结论  因此,氢能作为战略能源,其开发利用有助于促进我国能源与产业的绿色转型,但仍然面临诸多问题,需要合理布局,避免重复建设和低端技术的引进,才能保持氢能产业的又好又快发展。     

海上风电-氢能综合能源监控系统设计

  目的  针对大规模的海上风电投产后消纳问题，提出了海上风电－氢能综合能源监控系统。  方法  提出了海上风电－氢能综合能源监控系统的系统架构、分析了陆上加氢站、海上制氢站、海上风电机组各监控子系统的要求，并给出了能量管理的要求。  结果  实现了实时数据采集、顺序控制、发电预测及计划、分布式电源管理、制氢负荷管理的要求。  结论  系统达到了自发自用，短时储电，长期储氢，负荷可控的控制要求。方案切实可行，有望于工程应用推广。     

独立式海上风电制氢工艺设计

  目的  文章旨在为充分利用深远海优质的风资源,解决海上风电的弃风问题以及对未来新能源船舶提供一种可能的海上氢气燃料供给方式。  方法  论述了一种依托于独立式海上平台的海上风电耦合海水制氢技术的工艺流程,主要对关键设备——质子交换膜电解水制氢系统、氢气压缩机、氢气储罐及部分辅助设备的工艺设计问题进行阐述,简略说明了制氢平台的控制方案,并且对其经济性进行了初步分析。  结果  从工艺设计的角度对海上风电制氢平台上的设计仅在较为前期的阶段,关键设备的供应链市场处于发展初级时期且大部分供应商未进军海工市场,表明现今海上浮式制氢的工程设计到工程化还不成熟且可再生能源制氢经济性较差。  结论  目前,海上风电还无法做到平价上网,海洋风电耦合氢能应用还需要一个长期过程,进行工程试验是大规模工程化的前提。     

中国规模化氢能供应链的经济性分析

    目的   文章研究规模化氢能供应链的经济性，未来十年，氢能作为战略能源将会重构社会的能源结构，并影响未来社会能源总成本。预测大规模氢能时代的制氢、储氢、输氢、分销、应用的成本，和市场化的趋势有着重要的意义。氢气由于高储运成本，用途、品质的多样性，氢气市场存在分层结构。分析氢能与常规能源的可比价格，提出原油当量价格(POE)的概念，预测未来氢能价格的合理区间。解决供应链问题是获得低成本氢能的关键，由此提出干线门站模式，解决绿氢的资源分布与长距离输送氢能的问题。    方法   利用平准化氢气成本(LCOH)分析模型，测算大型光伏制氢管道输氢LCOH，分析大规模可再生能源制氢输氢的经济性。利用氢能供应链的储、输、卸六个象限成本公式，分析气氢、液氢、固氢、有机氢、管道氢等不同储运技术，短距离氢储运成本，分析门站后输氢的场景和成本，预测短距离输氢的成本趋势。    结果   研究表明:我国有丰富的绿氢资源，随着投资下降，预计大规模绿氢管道输送的城市门站LCOH将低于2.0 RMB/Nm3，将成为未来主要的氢源。当前，氢储运技术气氢、液氢、甲醇、合成氨、有机氢、固氢、管道氢，随着规模的增加实现远距离输送。在现有的技术下，城市门站到终端的输送，氢短距输送（<100 km）测算成本都在1.2 RMB/Nm3以下，由此评估的氢能供应链的总成本，干线门站模式下氢能最终到达终端的价格约为3.2 RMB/Nm3，当量价格POE与汽油价格接近，考虑燃料电池的能效因素，氢能汽车在4.0 RMB/Nm3的氢价下，具有比汽油车更低的百公里燃料费用。    结论   因此，氢能作为战略能源，在无补贴的情况下实现中国氢能源的绿氢替代，在技术经济上是可行的。     

中国氢能高质量发展的路径建议与政策探讨

  目的  在“双碳”目标下,中国氢能大有可为。基于中国氢能产业发展的现状,围绕存在的问题,对氢能高质量发展的路径和政策进行探讨。  方法  对国内外相关政策、文献和案例进行了梳理和分析,从路径和政策两个角度做了总结。  结果  在路径方面,利用氢能促进交通领域和工业领域的低碳化,将氢能与现有油气能源储运管网体系耦合,利用氢能促进可再生能源标准化,发展（光伏、风能等可再生能源发电）电解制氢,加大氢燃料电池商用推广等,是中国氢能高质量发展的有效保证;在政策方面,完善国家氢能的顶层政策设计,细化氢能“制储输用”专项研究的政策支持,加快制定氢能相关的标准和规范,加强氢能产业的战略联盟建设以及健全氢能市场供需协调等,是中国氢能高质量发展的重要保障。  结论  文章提及的相关的路径建议和政策探讨可为相关部门和行业人员提供一定参考。     

Recent progress in non-noble metal-based electrocatalysts for urea-assisted electrochemical hydrogen production

Water electrolysis is known as an efficient strategy in the direction of green energy production to remove fossil fuels and generate hydrogen. On the other hand, the slow kinetics of the anodic half-reaction (OER) significantly reduces the efficiency of this system. Therefore, choosing an alternative to OER has become a new and reliable approach. Urea oxidation reaction (UOR) is considered an excellent alternative to OER due to its low required potential (0.37V), the abundance of urea sources (industrial waste and human/animal urine), and harmless by-products (N₂, CO₂). Electrocatalysts based on non-noble metals such as nickel, cobalt, molybdenum, manganese, iron, and copper in electrochemical urea-assisted water splitting due to their high electrocatalytic performance and lower price than noble metals play an essential role in reducing costs and increasing the efficiency of this system. This review investigated the electrochemical water splitting reaction and its anodic and cathodic half-reactions. Then, urea, electro-oxidation of urea, methods of making catalysts, measuring parameters of electrocatalytic properties, solutions to improve performance, and types of non-noble catalysts used in this field were reviewed, and finally, challenges and solutions to improve results in the future were introduced.     

Spinel NiCo2O4 3-D nanoflowers supported on graphene nanosheets as efficient electrocatalyst for oxygen evolution reaction

Efficient oxygen evolution reaction (OER) electrocatalysts with non-noble metals are very critical for the large-scale exploitation of electrocatalytic hydrogen production systems. To improve the catalytic activity of OER electrocatalysts, several design strategies, such as construction of nanostructures, porous structures and composite materials have been proposed. Herein, spinel NiCo₂O₄ 3-D nanoflowers supported on graphene nanosheets (GNs) are prepared by a simple solvothermal synthesis method as non-noble metal electrocatalysts for OER. The present NiCo₂O₄/GNs composite integrates multiple advantages of nanostructures, porous structures and composite materials, including high surface area, abundant catalytic sites and high stability. Benefiting from the favorable features, the NiCo₂O₄/GNs composite exhibits a better OER performance than NiCo₂O₄ and RuO₂ in alkaline medium, which has a low onset potential (1.50 V), a small Tafel slope (137 mV dec⁻¹). The present work opens a new window for the construction of the carbon-supported 3-D nanostructure of transition metal catalysts with optimizable electrocatalytic performances for electrocatalytic hydrogen production.     

Nickel sulfide-based electrocatalysts for overall water splitting

Hydrogen is a green energy with sustainability and high energy density. Electrochemical water splitting (EWS) is a promising green strategy for hydrogen production. Noble metal electrocatalysts exhibit excellent electrocatalytic activity in EWS. However, the applications of noble metals in EWS are limited because of their scarcity and high price. Therefore, the research on non-noble metal electrocatalysts has attracted much attention. Among them, nickel sulfide electrocatalysts, with a unique 3D structure, pretty conductivity, and adjustable electronic structure, show significant electrocatalytic activity in hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). In this review, the mechanism of the electrocatalytic reaction, electrochemical parameters, and preparation methods of nickel sulfide are introduced first. Then, the five methods including atomic doping (including cations, anions and diatoms), morphological control, hybridization, integration with nanocarbon, and high-index facets exposure to regulate the electronic structure and active sites of nickel sulfide were illustrated, so as to improve the electrocatalytic activity of nickel sulfide. The electrocatalytic properties of these nickel sulfides were reviewed. However, there are some problems in the research of electrocatalysis, such as how to further improve the conductivity of the electrocatalyst, and the calculation method of current density is not unified. Therefore, our future development direction is to prepare a stable nickel sulfide electrocatalyst, study relevant strategies to simultaneously increase active sites and improve conductivity, and effectively make nickel sulfide into an EWS catalyst with higher performance.     

Recent developments in nickel based electrocatalysts for ethanol electrooxidation

A survey is done to gain a general idea in the development of various nickel based anode electrocatalysts for ethanol electrooxidation reaction. Platinum and other noble metal electrocatalysts are very well known but their cost and scarcity is a major issue hampering its use on a commercial level. Apart from cost, the poisoning of noble metal electrocatalysts due to CO is also another issue. These issues can be tackled by partially or fully replacing the noble metal electrocatalysts by non-noble metal electrocatalysts. The use of electrocatalytically active non-noble metal like nickel provides an excellent alternative. Hence, major thrust is laid upon the use of nickel in the form of either as a single or a complementary element in the electrocatalysts containing two (binary), three (ternary), four (quaternary) or more noble and/or non-noble metals to improve the electrocatalytic activity for ethanol electrooxidation reaction. The quality of an electrocatalyst is decided on a number of factors. Onset potential and current density are the two main parameters representing the activity of electrocatalysts. Complete oxidation of ethanol to give CO₂ is a major requirement to extract maximum current. Literature survey shows that support, synthesis approaches and elemental compositions greatly contributes to enhance the electrocatalytic performance of nickel based electrocatalysts towards ethanol electrooxidation reaction.     

Core-shell nanoarray structured La doped Cu(OH)2@NiCo layered double hydroxide for oxygen evolution reaction

Efficient hydrogen production via water splitting is significant because of the zero-carbon emission property. Developing low-cost and highly efficient electrocatalysts for the oxygen evolution reaction (OER), a key half-reaction of water splitting, is critical. Herein, we designed Cu(OH)₂@NiCo layered double hydroxide core-shell nanoarray supported on copper foam (CF) with different La doping amount (abbreviated as Cu(OH)₂@NiCoLa LDH/CF) via the facile electrodeposition method. Owing to the synergistic effect between La and NiCo LDH by electronic structure tuning, Cu(OH)₂@NiCoLa LDH/CF shows excellent OER performance with the lowest overpotential of 254 mV to drive the current density of 10 mA cm^?2 and outstanding long-term durability for 24 h. The idea of doping rare-earth metal into non-noble NiCo-based LDHs core-shell nanoarray structure in this work can inspire the design of other efficient electrocatalysts.     

Flower-like HEA/MoS2/MoP heterostructure based on interface engineering for efficient overall water splitting

The development of cheap, efficient, and active non-noble metal electrocatalysts for total hydrolysis of water (oxygen evolution reaction (OER) and hydrogen evolution reaction (HER)) is of great significance to promote the application of water splitting. Herein, a heterogeneous structured electrode based on FeAlCrMoV high-entropy alloy (HEA) was synthesized as a cost-effective electrocatalyst for hydrogen and oxygen evolution reactions in alkaline media. In combination of the interfacial synergistic effect and the high-entropy coordination environment, flower-like HEA/MoS₂/MoP exhibited the excellent HER and OER electrocatalytic performance. It showed a low overpotential of 230 mV at the current density of 10 mA cm⁻² for OER and 148 mV for HER in alkaline electrolyte, respectively. Furthermore, HEA/MoS₂/MoP as both anode and cathode also exhibited an overpotential of 1.60 V for overall water splitting. This work provides a new strategy for heterogeneous structure construction and overall water splitting based on high-entropy alloys.     

Carbon cloth/transition metals-based hybrids with controllable architectures for electrocatalytic hydrogen evolution - A review

Recently, the demand for energy consumption has been increasing exponentially due to the exhaustion of fossil fuels in the environment. This is the foremost technical challenge to the researchers to progress clean and alternative sustainable energy sources. Among various kinds of energy sources, an environment-friendly fuel, hydrogen is recognized as a favorable energy carrier to reduce the necessity on fossil fuels and protect the environment by reducing the discharge of greenhouse and other toxic gases. Thus, effective production and storage of hydrogen through a cost-effective and significant approach are the important factors of sustainable hydrogen production. Electrocatalytic water splitting is a favorable method for the hydrogen evolution reaction (HER), which requires an efficient and strong electrocatalyst to accelerate the kinetics of HER. To date, the well-developed electrocatalysts for HER activity are Pt-group metals, but, these electrocatalysts are inadequate and more expensive. In recent years, significant improvement has been achieved in the development of carbon cloth-based HER electrocatalysts as a replacement to Pt-based catalysts for hydrogen production in acidic medium. In this review, we mainly focused on the recent growth in the establishment of carbon-cloth functionalized transition metal (Fe-, Co-, Ni-, Mo-, and W-) based electrocatalysts towards the enhancement of HER activity. Depending on the results, we believed that the transition metal-based electrocatalysts have been appearing as fascinating and future alternative catalysts due to their morphology improvements, synergistic effects, a significant enhancement in the production of active sites, charge transfer efficiency, and superior HER activity with great durability. In addition, we outline the remarkable challenges and future prospects in this inspiring field.     

Directly application of bimetallic 2D-MOF for advanced electrocatalytic oxygen evolution

The development of non-noble oxygen evolution reaction (OER) catalysts with low energy consumption and cost is imperative to produce hydrogen energy from water splitting and enlarge its application. Two-dimensional (2D) metal organic frameworks (MOF) and their derivatives are widely regarded as promising electrocatalysts (EC) for OER due to its unique structural characteristics. Here, by optimizing the molar ratio of Ni to Co, bimetal 2-methylimidazole based 2D-MOF is synthesized and its derivatives are also obtained by phosphorization or oxidation. OER measurements prove that the original MOF structure with 5% Ni/Co molar ratio shows excellent activity with 310 mV overpotential (?) at the current density of 10 mA cm^?2 in 1 M KOH solution for OER, as well as a fairly good electrochemical stability rather than their oxidation or phosphorus derivatives. This work introduces a facile method to prepare bimetal imidazole-based 2D-MOF directly applied in energy conversion field without transformation, making a contribution for opening a new window of widely application of 2D-MOF and improving the hydrogen production efficiency from water splitting.     

Facile synthesis of polyoxometalate-based composite with doped ternary NiCoFe cations as electrocatalyst for oxygen evolution reaction

The construction of efficient and low-cost electrocatalysts for oxygen evolution reactions (OER) to replace precious catalysts is a necessity to achieve economic production of hydrogen. Herein, we report an efficient tri-metallic electrocatalysts for the OER that is prepared by incorporate nickel, cobalt and iron cations on Triton X-100/phosphotungstic acid organic-inorganic composite without utilize any binders or energy consumer procedure. Considering to the synergy effect of simultaneous absorption of NiCoFe cations on composite substrate, the as-made tri-metallic catalyst exhibits excellent OER activity with a small overpotential of 210 and 330 mV at a current density of 10 and 100 mA cm^?2, respectively. Moreover, remarkable trends in electrocatalytic activity of mono-, bi- and tri-metallic electrocatalysts at low (10 mA) and high (100 mA) current density are observed. In addition, this new families of non-precious metal catalyst shows long-term durability in 1 M KOH.