Superior Ion‐exchange Property of Amorphous Aluminosilicates Prepared by a Co‐precipitation Method

The development of inexpensive inorganic ion‐exchangers for the purification of environmental pollutants is a social demand. Amorphous aluminosilicates with a relatively high homogeneous Al environment are prepared by a feasible co‐precipitation method, i. e., mixing an acidic aluminum sulfate solution and basic sodium silicate solution, which exhibit excellent ion‐exchange selectivity for Cs⁺ and Sr²⁺. The K_d value for Sr²⁺ was comparable with that of zeolite 4A. The local structures and ion‐exchange behavior of the amorphous aluminosilicates are systematically investigated. The ion‐exchange property of the amorphous aluminosilicates can be tuned by changing the interaction between the exchangeable cation and the amorphous aluminosilicates. Also, the amorphous aluminosilicates can adsorb bulky cations that zeolites hardly adsorb due to the limitation of the miropore size of zeolites.     

Preparation of organomodified aluminosilicates for purification of biological solutions

Organomodified aluminosilicates for purification of biological solutions were prepared from a natural zeolite. The synthesis was performed by chemical deposition of chitosan on the zeolite surface followed by successive treatment with a solution of copper sulfate and a solution of potassium ferricyanide. The composition of sorbents was determined by elemental analysis. The physicochemical properties of the starting and modified zeolites were studied by the positron annihilation spectroscopy, IR spectroscopy, powder X-ray diffraction, and scanning electron microscopy, while the adsorption properties were examined by sorption of brilliant green. The adsorption behavior of the zeolites toward endotoxins was assessed. The sorbent containing the ferricyanide-chitosan complex was found to have the highest sorption capacity for lipopolyssacharides (endotoxins).     

Tailor and Control of Acidic Strength in Ordered Mesoporous Aluminosilicates by Using Preformed Zeolite Precursors

The acidic strength of ordered mesoporous aluminosilicates of MAS-2, MAS-3, MAS-7 and MAS-9 and microporous crystals of Y, L, beta, and ZSM-5 zeolites was systemically investigated by temperature-programmed desorption of ammonia (NH3-TPD). Due to the use of preformed zeolite precursors of Y, L, beta and ZSM-5, the ordered mesoporous aluminosilicates with distinguished acidic strength were obtained, being dependent on the type of preformed zeolite precursors. Therefore, the acidic strength of these mesoporous aluminosilicates could be tailored and controlled.     

己内酰胺绿色生产技术

中国石化石油化工科学研究院历经20年,成功开发出己内酰胺绿色生产技术,建成3套20万t/a工业生产装置、多套工业装置正在建设中.己内酰胺绿色生产技术包括:钛硅分子筛与浆态床集成用于环己酮氨肟化合成环己酮肟;纯硅分子筛与移动床集成用于环己酮肟气相重排;非晶态合金催化剂与磁稳定床集成用于己内酰胺精制.工业实施后,装置投资下降70%、生产成本下降10%、原子利用率由60%提高到90%以上、三废排放是已有技术路线的1/200、无副产物硫酸铵.己内酰胺绿色生产技术产生了重大的经济效益和社会效益,践行了绿色化学的理念,是绿色化学的成功范例.     

Recent advances in removal of toxic elements from water using MOFs: A critical review

Water pollution with potentially toxic trace elements (PTEs) has seriously threatened the environment and human health globally. Their widespread occurrence at varied toxic levels and in different chemical forms has made remediation measures a cumbersome task. Furthermore, recent trends of PTE release via natural and/or human sources have further portended numerous detrimental events. Hence, effective remediation of PTE-contaminated aqueous media is highly substantial. Among various adsorbents, metal–organic frameworks (MOFs) have been recently characterized and tested being versatile and highly effective adsorbents for remediating pollutant/PTE-contaminated aqueous media. Owing to their plethora of structures and numerous intrinsic characteristics (high adjustability, porosity, surface area, selectivity, reusability, and structural stability), MOFs have lately received an obvious consideration in environmental remediation and analytical chemistry. This review initially summarized the most recent data (2018–2022) about PTE water contamination (rivers, lakes, canals, groundwater, city, and industrial wastewater). Then the review comprehensively highlighted the effects of synthesis techniques/conditions and post-synthetic functionalization’s on MOF structural morphology by critically conferring the underlying mechanisms. Review summarizes MOF limitations apropos their large-scale industrial applications. The latest advancements regarding MOF syntheses and structural morphology to enhance their industrial applications have been updated and critically discussed. Likewise, the stability, selectivity, reusability, and multi-metal/pollutant removal potential of MOFs have been delineated using recent findings. Finally, the future perspectives have been put forth keeping in view the recent trends and potential research gaps. This review will act as guidelines for future studies of MOF-mediated PTE removal from wastewaters.     

Integrating social and environmental justice into the chemistry classroom: a chemist’s toolbox

ABSTRACT

Although the chemical enterprise has provided numerous contributions to humanity, unintended consequences contribute to a disproportionate exposure of hazardous chemicals to certain populations based on race and socioeconomic status. Integrating concepts of social and environmental justice within chemistry curriculum provides an educational framework to help mitigate these impacts by training the next generation of chemists with justice-centered and green chemistry principles to guide their future work. Green and sustainable chemistry technologies can contribute to social equity and environmental justice. However, equity and social justice have only recently become a significant part of the green chemistry conversation. This article summarizes how the authors have explored issues of equity and environmental justice with the green and sustainable chemistry community. It offers a toolbox for college and university instructors containing foundational language, research, and idea-generation that can be used to strengthen the transition of a traditional chemistry curriculum toward a justice-centered one.     

A copper diimine‐based honeycomb‐like porous network as an efficient reduction catalyst

Nitrophenols are among the widely used industrial chemicals worldwide; however, their hazardous effects on environment are a major concern nowadays. Therefore, the conversion of environmentally detrimental p‐nitrophenol (PNP) to industrially valuable p‐aminophenol (PAP), a prototype reaction, is an important organic transformation reaction. However, the traditional conversion of PNP to PAP is an expensive and environmentally unfriendly process. Here, we report a honeycomb‐like porous network with zeolite‐like channels formed by the self‐organization of copper, 1,10‐phenanthroline, 4,4′‐bipyridine, and water. This porous network effectively catalyzed the transformation of hazardous PNP to pharmaceutically valued PAP. In the presence of complex, PNP to PAP conversion occurred in a few minutes, which is otherwise a very sluggish process. To assess the kinetics, the catalytic conversion of PNP to PAP was studied at five different temperatures. The linearity of lnC_t/C_o versus temperature plot indicated pseudo‐first‐order kinetics. The copper complex with zeolite like channels may find applications as a reduction catalyst both on laboratory and industrial scales and in green chemistry for the remediation of pollutants.     

可用于环境修复的半导体光催化剂及其改性策略研究进展

多相光催化技术作为一种直接利用太阳光降解多种污染物的先进氧化工艺在环境修复领域的研究中引起了广泛关注.在多相光催化过程中,半导体材料在太阳光的激发下,其强大的氧化/还原能力可快速高效降解各种污染物.研究者通常根据环境中污染物的状态和种类选择合适的半导体材料及修饰策略,构建高效多相光催化体系,探究光催化材料在环境修复中的...     

Use of zeolite to refold a disulfide-bonded protein

Zeolites are microporous crystalline aluminosilicates with a highly ordered structure. Using zeolite beta as an adsorbent, denatured/reduced hen egg lysozyme was refolded to the active form at high concentrations. The denatured/reduced lysozyme was adsorbed onto the zeolite and the protein was refolded by desorbing it into refolding buffer, consisting of redox reagents, guanidine hydrochloride, polyethylene glycol, and L-arginine. This zeolite refolding method could be highly effective for various kinds of proteins, refolding them with high efficiency even when they contain disulfide bonds.     

充满生机和科学机遇的磷化学研究所

简要地综述了第十五届国际磷化学会议的报告内容，介绍了目前磷化学的主要 研究领域，包括不对称合成、配合化学，生物碱化学，药物化学，农业化学等相关 领域的研究动态及新进展。     

Co-pyrolysis of biomass and waste plastics for production of chemicals and liquid fuel: A review on the role of plastics and catalyst types

The increasing global fuel consumption and growing environmental concerns are the impetuses to explore alternative energy that is clean and renewable for fuel production. Converting biomass and plastic waste into high-value fuel and chemicals via co-pyrolysis technique may provide a sustainable remediation to this problem. This review critically discussed the influence of various types of plastic wastes as co-reactant in co-pyrolysis with biomass on the product distribution, synergistic effect, and quality of bio-oil. The outcome of this review revealed that the addition of plastic enhanced the yield and quality of bio-oil and inhibited the production of oxygenated compound and coke formation. Next, the critical role of zeolite-based catalyst (microporous, mesoporous, hierarchical, and metal modified zeolite) and low-cost mineral-based catalyst in upgrading the yield and quality of liquid fuel were compared and discussed. The characteristic, synthesis method, strength, and limitation of each catalyst in upgrading the products were summarized. Hierarchical zeolites can resolve the problems of mass transfer, and diffusion limitation of large molecules into active sites associated with conventional zeolite due to the combination of two levels of porosity. Finally, the potential challenges and future directions for this technique were also suggested.     

以微孔β沸石为硅铝源合成强酸性介孔分子筛

以微孔β沸石为硅铝源,通过碱处理和以十六烷基三甲基溴化铵为模板剂,合成了具有较强酸性的六方结构介孔分子筛材料B-MCM-41,并采用XRD、N₂吸附脱附、FT-IR、²7Al MAS NMR、HRTEM和水热处理等手段对其进行了结构表征,采用NH₃-TPD对其进行了酸性表征。实验结果表明,B-MCM-41具有明显强于常规介孔分子筛的酸性,且在C⁺₁0混合芳烃加氢脱烷基化反应中表现出了良好的催化性能。这主要是由于碱溶液将β沸石降解为沸石结构单元,在表面活性剂作用下五元环次级结构单元被引入了介孔铝硅酸盐B-MCM-41的结构。     

稀土/L型沸石主-客体发光功能材料的研究进展

沸石微孔晶体材料作为客体功能物种的主体材料在主-客体组装化学中发挥着越来越重要的作用,在微型激光器、非线性光学、生物成像、光放大及光显示等高技术领域已显示出广阔、诱人的发展前景.本文介绍国内外,特别是河北工业大学在稀土/L型沸石主-客体杂化功能材料的组装、结构及其发光性能的研究工作,具体包括：稀土有机配合物在L沸石孔道内的组装、L型沸石-有机高分子透明杂化发光材料的制备及稀土有机配合物诱导控制的L型沸石自组装等.此外,本文对稀土/L型沸石主-客体杂化发光功能材料的研究进行了展望.     

A review on the green synthesis of hierarchically porous zeolite

Conventional bottom-up and top-down methods for synthesizing hierarchical zeolite have led to complicated economic and environmental issues due to the requirement of expensive and hazardous organic molecules, the large amount of acid/base solution, high energy, and expensive starting materials. Besides, the bottom-up method through the hydrothermal crystallization evokes safety issues due to the high autogenous pressure. Accordingly, considerable efforts have been made to develop green route synthesis of hierarchical zeolite by eliminating the use of a solvent (solvent-free), utilizing sustainable starting materials and green secondary template (mesoporogen), as well as eliminating the use of mesoporogen (mesoporogen-free). Other routes, including recycling of mother liquor, steam-assisted conversion, gel-like-solid phase method, and silanization, are also elaborated, as they are reported to promote a green and facile approach for the synthesis of hierarchical zeolites. In this review, we provide recent progress on the development of the green synthesis of hierarchically porous zeolite.     

Inorganic molecular sieves: Preparation,modification and industrial application in catalytic processes

The increasing environmental concern and promotion of “green processes” are forcing the substitution of traditional acid and base homogeneous catalysts by solid ones. Among these heterogeneous catalysts, zeolites and zeotypes can be considered as real “green” catalysts, due to their benign nature from an environmental point of view. The importance of these inorganic molecular sieves within the field of heterogeneous catalysis relies not only on their microporous structure and the related shape selectivity, but also on the flexibility of their chemical composition. Modification of the zeolite framework composition results in materials with acidic, basic or redox properties, whereas multifunctional catalysts can be obtained by introducing metals by ion exchange or impregnation procedures, that can catalyze hydrogenation–dehydrogenation reactions, and the number of commercial applications of zeolite based catalysts is continuously expanding.In this review we discuss determinant issues for the development of zeolite based catalysts, going from zeolite catalyst preparation up to their industrial application. Concerning the synthesis of microporous materials we present some of the new trends moving into larger pore structures or into organic free synthesis media procedures, thanks to the incorporation of novel organic templates or alternative framework elements, and to the use of high-throughput synthesis methods. Post-synthesis zeolite modification and final catalyst conformation for industrial use are briefly discussed.In a last section we give a thorough overview on the application of zeolites in industrial processes. Some of them are well established mature technologies, such as fluid catalytic cracking, hydrocracking or aromatics alkylation. Although the number of zeolite structures commercially used as heterogeneous catalysts in these fields is limited, the development of new catalysts is a continuous challenge due to the need for processing heavier feeds or for increasing the quality of the products. The application of zeolite based catalysts in the production of chemicals and fine chemicals is an emerging field, and will greatly depend on the discovery of new or known structures by alternative, lower cost, synthesis routes, and the fine tuning of their textural properties. Finally, biomass conversion and selective catalytic reduction for conversion of NOx are two active research fields, highlighting the interest in these potential industrial applications.     

沸石分子筛的表面改性技术进展

沸石分子筛的改性技术与这类材料的合成及应用一样相当大地推动了沸石化学的发展。本篇文章引用了至少90篇文献概括地介绍了最近发展起来的三种沸石表面改性方法:沸石内配位化学、化学蒸汽沉积和沸石的表面有机金属化学。     

Spectroscopic signatures of nitrogen-substituted zeolites

Nanoporous acid catalysts such as zeolites form the backbone of catalytic technologies for refining petroleum. With the promise of a biomass economy, new catalyst systems will have to be discovered, making shape-selective base catalysts especially important because of the high oxygen content in biomass-derived feedstocks. Strongly basic zeolites are attractive candidates, but such materials are notoriously difficult to make due to the strong inherent acidity of aluminosilicates. Several research groups have endeavored to produce strongly basic zeolites by treating zeolites with amines, but to date there is no compelling evidence that nitrogen is incorporated into zeolite frameworks. In this communication, we detail synthesis, NMR spectroscopy, and quantum mechanical calculations showing that nitrogen adds onto both surface and interior sites while preserving the framework structure of zeolites. This finding is crucial for the rational design of new biomass-refinement catalysts, allowing 50 years of zeolite science to be brought to bear on the catalytic synthesis of biofuels.     

Modelling studies of water in crystalline nanoporous aluminosilicates

The paper presents a review of molecular modelling studies of hydrated nanoporous aluminosilicates (zeolites and clays) performed during the last decade. A special emphasis is set on the calculation of the dynamical quantities and collective properties of the confined water. Some new results concerning the behaviour of water molecules in the siliceous silicalite and zeolite beta structures are presented.     

CO2参与电化学构筑C—N键制备重要化学品

CO₂是主要的温室气体, 同时也是重要的C1资源. 通过构筑C—N键制备重要化学品在化工、 生物合成及医药等领域应用广泛. 近年来, 随着碳中和与绿色化学理念的不断深化, 电化学构筑C—N键的策略也因其环保、 低碳、 简单及绿色等优势而受到关注. 同时, 由于化石燃料不断消耗带来的资源与环境问题, 重要化学品及燃料的绿色合成也成为科技发展战略中的重中之重. 本文归纳了CO₂参与构建C—N键制备重要化学品方面的研究进展; 从催化体系构建、 反应过程和机理的角度对电化学合成尿素、 酰胺和胺进行了综述; 最后针对目前研究中面临的挑战, 对这一领域的未来发展进行了展望.