基于MES的CO2减排与高价值有机物转化研究进展

微生物电化学系统（MES）是一种可选择的CO₂减排利器,能够在降解温室效应的同时将CO₂转化为高价值有机物,解决CO₂的能源与资源化问题,因此受到了极大关注。MES系统是一种电驱动的生物电化学电子转移系统,可驱动CO₂转化为高价值C₁～C_n有机物。电活性微生物（EAB）的胞外电子传递效率是提高MES转化效率的关键因素。因此,探索解析电活性微生物胞外电子转移规律和转化过程的影响因素,有望揭示MES的微观机理,提高MES的转化效率,突破MES商业化发展瓶颈。     

微生物燃料电池的研究进展及发展趋势探讨

微生物燃料电池是将废水中有机物的化学能转化为电能,在去除污染物的同时将产生的电能回收,实现了能量转化。本文系统介绍了微生物燃料电池的研究进展,在对微生物燃料电池的产电微生物、电极材料、微生物燃料电池的放大、微生物燃料电池的实际应用等方面总结的基础上,指出了微生物燃料电池研究的发展方向,其中筛选改造产电微生物对不同底物的耐受性和适应性、开发廉价高效的电极材料、构造大型微生物燃料电池堆以及微生物电化学物质合成等是未来研究的重点。     

促进微生物胞外电子转移的纳米材料研究进展

胞外电子转移（EET）是产电微生物在代谢过程中将自身产生的电子转移到外部电子受体的过程，然而较缓慢的胞外电子转移速率显著影响了微生物燃料电池（MFCs）的产电性能，提高胞外电子转移的效率对推动微生物燃料电池的大规模应用具有重要意义。纳米材料具备优异的导电性、稳定性以及生物相容性，对改善阳极与产电微生物之间的电子传递速率具有重要作用。该文综述了胞外电子转移的主要路径，阐述了不同种类的纳米材料在促进胞外电子转移过程中的机理和其对应的MFCs产电性能，并展望了纳米材料强化微生物EET过程在微生物电化学技术利用方面的研究前景。     

合成生物学方法改造电活性生物膜研究进展

电活性生物膜是由电能细胞分泌的胞外多糖、蛋白、胞外DNA（extracellular DNA, eDNA）、菌毛等成分聚集,与细胞本身相互交联形成的导电多聚体。以多菌群落形态展现,在微生物燃料电池、微生物电合成、高值化学品生产、重金属污染处理、医疗等领域中具有至关重要的作用,是微生物电催化系统研究的核心之一。但自然状态下的电活性生物膜因厚度、结构稳定性、生物量等因素的限制,严重制约了电子传递效率。综述了近五年利用合成生物学改造电活性生物膜的研究进展,系统探讨了工程生物膜的构建、结构成分、导电性能以及应用,为将来进一步实现高效电催化奠定基础。     

水溶液中电化学还原CO2的研究进展

CO₂作为一种潜在的碳资源,寻找一种有效的方法转移利用CO₂一直是社会关注的焦点。水溶液中电化学方法转化固定CO₂可在室温和常压下进行,通过选择不同电极和电极电势来改变产物、调控反应速率和选择性,因而具有潜在的优势。本文综述了水溶液中电化学还原CO₂的发展现状,介绍了水溶液中电还原CO₂的基本原理和电极上发生的主要反应;总结了水溶液中金属电极、气体扩散电极(GDEs)和复合电极等不同电极材料对CO₂还原产物的种类、选择性以及电流效率的影响;讨论了温度、CO₂分压等还原反应条件对反应速率和电流效率的影响。展望了水溶液中电还原CO₂技术的发展前景,认为利用水基溶液中丰富的[H],增强CO₂还原产物的燃料化程度,将在环境保护、资源利用和经济效益方面具有极大价值,符合绿色化学发展理念。     

金属氧化物催化CO2与甲醇合成碳酸二甲酯的研究进展

CO₂是主要的温室气体。近年来随着工业的大力发展,CO₂的排放量迅猛增加,严重影响着人类的生存环境。将CO₂转化成有价值的化工产品,受到了研究领域的广泛关注。其中将CO₂与产能过剩的甲醇作为原料,生产碳酸二甲酯（DMC）,既能减少CO₂排放,又能产生有价值的绿色产品DMC。本文简述了影响CO₂转化的因素,即受热力学限制和CO₂活化困难;重点介绍了具有酸碱活性中心的金属氧化物ZrO₂、CeO₂以及复合金属氧化物催化剂的催化性能和反应机理,并分析了影响催化活性的主要原因：表面酸碱性能决定了催化活性;进一步分析了催化剂表面的酸碱性来源于Lewis酸碱位和Br?nsted酸性位。对于开发高效的金属氧化物催化剂未来的研究方向提出了展望: 通过调控催化剂的晶相和形貌、增加氧空位和羟基官能团、掺杂碱性或者酸性物种来改变催化剂表面的酸碱性,并且向催化系统中添加脱水剂。最后指出了由于CO₂分子的稳定性很难被活化,需进一步深入研究其活化CO₂的机理,提高CO₂的转化率。     

Cu基催化材料在CO2转化中的应用

综述了近年来Cu基催化材料用于CO2资源化利用的研究进展,介绍了其在热催化加氢、电催化和光催化等技术中的最新研究,指出了目前研究中存在的问题和不足,并对其未来的研究方向进行了前景展望.     

纳米材料介导微生物胞外电子传递过程的研究进展

微生物胞外电子传递（EET）过程在自然界中普遍存在,并且在能源利用和环境修复等方面具有广阔的应用前景,但是低效的电子传递一直是其在实际应用中的关键瓶颈。纳米材料具有独特的表面效应、体积效应、量子尺寸及宏观量子隧道效应等性质,引入纳米材料与电活性微生物相结合实现优势互补,可以缩短电荷转移路径,从而提高EET效率。本文综述了EET方式,以及纳米材料的电子转移能力、氧化还原电势、表面结构与性质、生物相容性及纳米材料-微生物的界面构筑对EET过程的影响,重点阐述了纳米材料与电活性微生物界面构筑的各种策略,并讨论了这些策略的适用性和局限性,最后展望了纳米材料强化电活性微生物EET的未来研究方向。     

电极改性强化微生物燃料电池产电同步降解有机污染物研究进展

微生物燃料电池(MFC)是一种利用微生物作为催化剂就能实现同步产电及降解有机污染物的绿色能源装置.电极作为MFC的重要组成部分,在提高污染物降解及产电能力方面发挥着至关重要的作用.介绍了MFC电极,主要包括碳基/合成材料修饰电极、导电聚合物/复合物修饰电极、金属/金属氧化物修饰电极及其他材料修饰电极及其最新研究进展,对...     

Electron transfer pathways in microbial oxygen biocathodes

The ability of some bacteria to enhance the rate of cathodic oxygen reduction to water has been recently discovered, opening the way to an entirely renewable and environmentally friendly concept of biocathode. In this study we reveal that several mechanisms may induce catalytic effects by bacteria. These comprise mechanisms that are putatively beneficial to the bacteria as well as mechanisms which are merely side effects, including quinone autoxidation and direct O₂ reduction by heme compounds. Here we showed that 1 μM of ACNQ is able to generate a significant catalytic wave for oxygen reduction, with onset at approximately 0 V vs. SHE. Similarly, adsorption of hemin on a carbon surface catalyses O₂ reduction to H₂O₂ with an onset of +0.2 V vs. SHE. To evaluate the catalytic pathways of live cells on cathodic oxygen reduction, two species of electrochemically active bacteria were selected as pure cultures, namely Acinetobacter calcoaceticus and Shewanella putrefaciens. The former appears to exploit a self-excreted redox compound with redox characteristics matching those of pyrroloquinoline quinone (PQQ) for extracellular electron transfer. The latter appears to utilise outer membrane-bound redox compounds. Interaction of quinones and cytochromes with the membrane-bound electron transfer chain is yet to be proven.     

Co anchored on porphyrinic triazine-based frameworks with excellent biocompatibility for conversion of CO2 in H2-mediated microbial electrosynthesis

Microbial electrosynthesis is a promising alternative to directly convert CO₂ into long-chain compounds by coupling inorganic electrocatalysis with biosynthetic systems. However, problems arose that the conventional electrocatalysts for hydrogen evolution may produce extensive by-products of reactive oxygen species and cause severe metal leaching, both of which induce strong toxicity toward microorganisms. Moreover, poor stability of electrocatalysts cannot be qualified for long-term operation. These problems may result in poor biocompatibility between electrocatalysts and microorganisms. To solve the bottleneck problem, Co anchored on porphyrinic triazine-based frameworks was synthesized as the electrocatalyst for hydrogen evolution and further coupled with Cupriavidus necator H16. It showed high selectivity for a four-electron pathway of oxygen reduction reaction and low production of reactive oxygen species, owing to the synergistic effect of Co–N_x modulating the charge distribution and adsorption energy of intermediates. Additionally, low metal leaching and excellent stability were observed, which may be attributed to low content of Co and the stabilizing effect of metalloporphyrins. Hence, the electrocatalyst exhibited excellent biocompatibility. Finally, the microbial electrosynthesis system equipped with the electrocatalyst successfully converted CO₂ to poly-β-hydroxybutyrate. This work drew up a novel strategy for enhancing the biocompatibility of electrocatalysts in microbial electrosynthesis system.     

油田燃煤电厂CO_2捕集纯化工程实践

CO2是一种温室气体,通过CO2收集、驱油技术,能将造成温室效应的气体用于提高原油采收率,同时减少工业生产中温室气体的排放。为了实现CO2的捕集纯化,胜利油田采用一乙醇胺溶液(MEA)化学吸收工艺捕集CO2。介绍了"低渗透油藏CO2驱油"重大先导试验,在胜利发电厂建设CO2捕集纯化装置,通过此装置收集稳定、廉价的CO2气体用于驱油生产实践。通过分析系统运行状况,对装置进行了一系列的试验、研究,总结了大量CO2捕集系统的工程应用经验。胜利油田CO2捕集项目,通过将大型燃煤电厂烟道气中CO2捕集纯化、安全输送等系列技术攻关,形成低能耗捕集纯化、运输的集成配套技术。     

Recent advances in polymeric membranes for CO2 capture

Membrane and membrane process have been considered as one of the most promising technologies for mitigating CO₂ emissions from the use of fossil fuels. In this paper, recent advances in polymeric membranes for CO₂ capture are reviewed in terms of material design and membrane formation. The selected polymeric materials are grouped based on their gas transport mechanisms, i.e., solution‐diffusion and facilitated transport. The discussion of solution‐diffusion membranes encompasses the recent efforts to shift the upper bound barrier, including the enhanced CO₂ solubility in several rubbery polymers and novel methods to construct shape-persisting macromolecules with unprecedented sieving ability. The carrier-bearing facilitated transport membranes are categorized based on the specific CO₂-carrier chemistry. Finally, opportunities and challenges in practical applications are also discussed, including post-combustion carbon capture (CO₂/N₂), hydrogen purification (CO₂/H₂), and natural gas sweetening (CO₂/CH₄).     

Effects of plant residues on crop performance, N mineralisation and microbial activity including field CO2 and N2O fluxes in unfertilised crop rotations

The impacts of crop rotation and input of organic matter in the form of green manure crops, straw residues and incorporation of catch crops on crop yield, nitrogen uptake, microbial biomass and activity were studied in unfertilised crop rotations differing in input of plant residues, i.e., high-input rotations with a grass-clover crop and catch crops included and low-input cereal rotations without catch crops. The parameters studied included substrate induced respiration (SIR), hydrolysis of fluorescein diacetate (FDA), arylsulfatase activity (ASA), N mineralisation, N₂O emission, and soil respiration. These parameters were measured in bare soil plots, to estimate the effects of previous years' crops and input of plant residues. In neighbouring plots crop performances were registered by measuring yields, above-ground biomass and nitrogen uptake during the growing season. Generally, all measured parameters were significantly higher in the high-input than in low-input rotations. Estimates of metabolic quotients indicated that the microbial communities in the low-input rotations were less efficient in utilising the C sources than those in the high-input rotations. Calculations of N₂O emission factors indicate that the current IPCC methodology for estimating N₂O emission from plant residues needs to be improved.     

An efficient methodology for utilization of K-feldspar and phosphogypsum with reduced energy consumption and CO2 emissions

The issues of reducing CO2 emissions, sustainably utilizing natural mineral resources, and dealing with industrial waste offer challenges for sustainable development in energy and the environment. We propose an efficient methodology via the co-reaction of K-feldspar and phosphogypsum for the extraction of soluble potassium salts and recovery of SO2 with reduced CO2 emission and energy consumption. The results of characterization and reactivity evaluation indicated that the partial melting of K-feldspar and phosphogypsum in the high-temperature co-reaction significantly facilitated the reduction of phosphogypsum to SO2 and the exchange of K+(K-feldspar) with Ca2+(CaSO4 in phosphogypsum). The reaction parameters were systematical y investigat-ed with the highest sulfur recovery ratio of~60%and K extraction ratio of~87.7%. This novel methodology possesses an energy consumption reduction of~28%and CO2 emission reduction of~55%comparing with the present typical commercial technologies for utilization of K-feldspar and the treatment of phosphogypsum.     

Metal oxide-doped Ni/CaO dual-function materials for integrated CO2 capture and conversion: Performance and mechanism

Integrated CO₂ capture and conversion (ICCC) into valuable chemicals such as CH₄ and CO is a promising approach to mitigate anthropogenic CO₂ emissions. In this work, we prepared a series of metal oxide (M_xO_y, M = Mg, Al, Mn, Y, Zr, La, and Ce)-doped Ni/CaO dual-function materials (DFMs) and applied them to the ICCC process. The property–performance relationship of the DFMs was studied, and the conversion mechanism of the captured CO₂ was explored. For any DFM at any ICCC cycle (20 cycles in total), the CO₂ captured at the carbonation stage was completely released as CH₄, CO, and CO₂ at the conversion stage. Among all DFMs, Ni/CaZr(O) showed the best ICCC performance because of its good thermal stability. The conversion of captured CO₂ on the DFMs proceeded via a two-step mechanism, where CO₂ was first released from CaCO₃ and then converted into CH₄ at Ni sites and CO at CaO sites.     

Immobilization of carbonic anhydrase for facilitated CO2 capture and separation

Carbonic anhydrase (CA) as a typical metalloenzyme in biological system can accelerate the hydration/dehydration of carbon dioxide (CO₂, the major components of greenhouse gases), which performer with high selectivity, environmental friendliness and superior efficiency. However, the free form of CA is quite expensive (~ RMB 3000/100 mg), unstable, and non-reusable as the free form of CA is not easy for recovery from the reaction environment, which severely limits its large-scale industrial applications. The immobilization may solve these problems at the same time. In this context, many efforts have been devoted to improving the chemical and thermal stabilities of CA through immobilization strategy. Very recently, a wide range of available inorganic, organic and hybrid compounds have been explored as carrier materials for CA immobilization, which could not only improve the tolerance of CA in hazardous environments, but also improve the efficiency and recovery to reduce the cost of large-scale application of CA. Several excellent reviews about immobilization methods and application potential of CA have been published. By contrast, in our review, we stressed on the way to better retain the biocatalytic activity of immobilized CA system based on different carrier materials and to solve the problems facing in practical operations well. The concluding remarks are presented with a perspective on constructing efficient CO₂ conversion systems through rational combining CA and advanced carrier materials.     

不同浸渍时间对CuO/Cu@BC电极催化CO2还原性能的影响

将具有3D网状结构的细菌纤维素(BC)膜作为催化剂载体,通过原位化学还原法制备了负载Cu和CuO纳米复合材料的催化剂电极(CuO/Cu@BC),并通过改变BC膜的浸渍时间实现电极结构调控以探索最佳条件。结果表明,具有3D球形结构的CuO/Cu24h@BC电极对CO2还原表现出较好的电子传输性能和更高的电流密度。CuO/Cu24h@BC电极的电化学比表面积最大,达12 mF/cm2。CuO/Cu24h@BC电极可将CO2电催化转化为CO,且产生CO的法拉第效率为52%。     

NO removal performance of CO in carbonation stage of calcium looping for CO2 capture

Calcium looping realizes CO2 capture via the cyclic calcination/carbonation of CaO.The combustion of fuel supplies energy for the calciner.It is unavoidable that some unburned char in the calciner flows into the carbonator,generating CO due to the hypoxic atmosphere in the carbonator.CO can reduce NO in the flue gases from coal-fired power plants.In this work,NO removal performance of CO in the carbonation stage of calcium looping for CO2 capture was investigated in a bubbling fluidized bed reactor.The effects of carbonation temperature,CO concentration,CO2 capture,type of CaO,number of CO2 capture cycles and presence of char on NO removal by CO in carbonation stage of calcium looping were discussed.CaO possesses an efficient catalytic effect on NO removal by CO.High temperature and high CO concen-tration lead to high NO removal efficiency of CO in the presence of CaO.Taking account of better NO removal and CO2 capture,the optimal carbonation temperature is 650 ℃.The carbonation of CaO reduces the catalytic activity of CaO for NO removal by CO due to the formation of CaCO3.Besides,the catalytic performance of CaO on NO removal by CO gradually decreases with the number of CO2 capture cycles.This is because the sintering of CaO leads to the fusion of CaO grains and blockage of pores in CaO,hin-dering the diffusion of NO and CO.The high CaO content and porous structure of calcium-based sorbents are beneficial for NO removal by CO.The presence of char promotes NO removal by CO in the carbonator.CO2/NO removal efficiencies can reach above 90％.The efficient simultaneous NO and CO2 removal by CO and CaO in the carbonation step of the calcium looping seems promising.