The chemical fixation of CO2 into high value-added cyclic carbonates over metal- and cocatalyst-free heterogeneous catalyst has attracted considerable attention and is still a challenge. Rationally integrating multifunctional units into porous materials has been regarded as a promising strategy to enhance catalytic efficiency. In this study, the poly (ionic liquid)-hierarchical covalent organic framework (R-PIL-COF, R refers to CH2NH2/CH2OH/COOH/CH3) hybrids were successfully fabricated via in situ copolymerization of vinyl-containing covalent organic framework and hydrogen bond donors (HBDs)-functionalized imidazolium ionic liquids. Among, CH2NH2-PIL-COF hybrid bearing acidic and basic sites possess moderate CO2 adsorption ability and hierarchical pore structure which promoted the activation of CO2 and epichlorohydrin. Furthermore, the influence on the catalytic activity of various HBD groups and grafting amounts of poly (ionic liquid)s were systematically investigated, and CH2NH2-PIL-COF-45 % exhibited an exceptional catalytic performance under mild conditions (100 degrees C and 1 MPa CO2 pressure). Additionally, CH2NH2-PIL-COF-45 % had broad substrate tolerance and excellent stability. Finally, a synergistic catalytic mechanism was proposed based on the experimental and characterization results. The strategy of co-polymerizing ionic liquids to COF provides a new way to develop efficient COF-based hybrids by the integration of nucleophilic units into the COF skeleton for CO2 fixation under cocatalyst-free and mild conditions.

The transformation of CO2 into high value-added chemicals such as cyclic carbonates provide a promising technology to solve the exceeding CO2 emission. In the absence of solvent and co-catalyst, the development of highly efficient and recyclable metal-free catalyst with excellent performance under mild conditions still remains a great challenge. Herein, a series of multifunctional ionic covalent organic frameworks (COFs) was synthesized via post-synthesis modification strategy of covalently grafting functionalized imidazole on triazine-based COF skeleton. The influence of bridged alkyl chain, imidazole functional group, nucleophile and grafting amount on catalytic activity was investigated in the cycloaddition of CO2 with epichlorohydrin. Remarkably, IM-COF-Br-Vinyl could afford 96.49% yield and > 99% selectivity with a turnover frequency (TOF) value of 5434 h(-1) at 0.5 MPa CO2 pressure and 100 degrees C for 6 h, which was superior to other reported COF catalysts. The excellent catalytic performance was mainly ascribed to its excellent CO2 adsorption capacity and the synergistic effect of CO2-philic basic sites, hydrogen bond donors and nucleophilic anions. Additionally, the reusability and versatility of the catalyst was considered and the proposal catalytic mechanism was speculated according to the above conclusions. This strategy not only avoided the environmental pollution caused by catalytic system itself but also ensured the safety and low-energy consumption by realizing highly efficient catalytic conversion of CO2 under mild conditions. This provides an effective avenue for the design and synthesis of ionic liquid functionalized COF catalysts and the development of CO2 activation and utilization.

文章探究了"一带一路"合作国家中金融服务贸易竞争力较强的卢森堡、马耳他、塞浦路斯、黎巴嫩、新加坡五国与中国的金融服务贸易互补性关系,进而分别分析影响中国与这五国金融服务贸易互补性的因素,提出今后中国在金融服务贸易的发展上应侧重于转变经济增长方式、构建专业化的金融服务贸易合作平台以及培养满足市场需求的金融人才.

低碳城市是我国在面对高碳排放压力的情况下开展的试点政策,这一政策的推行表明了中国在碳减排方面的决心,更指明了我国未来经济、社会发展和前进的方向,即可持续发展.作为分行业二氧化碳排放量中位列第三的物流行业在该政策的影响下如何发展是现阶段试点城市物流业需要关注的问题.

"一带一路"倡议提出以来,沿线国家在金融服务贸易方面的交流与合作不断深化.研究发现:"一带一路"沿线国家的金融服务贸易进出口总额和增速发展水平呈现分层化,总体来看金融服务贸易发展程度中等偏下.但中国与"一带一路"沿线国家在金融服务贸易上存在较强的贸易互补性,与乌兹别克斯坦、柬埔寨、埃及等国家存在双向互补关系.沿线国家彼此之间要借助"一带一路"倡议的"东风"发展金融服务贸易,我国也要逐渐通过"放管服"帮助金融机构"走出去".