二氧化碳(CO_(2))是主要的温室气体,但同时也是一种储量巨大、廉价、安全且易得的可再生资源。在我国“碳达峰、碳中和”战略目标的驱动下,如何有效减少CO_(2)排放并转而利用这一重要碳资源已成为当前的研究热点与重点,这同时也加快了CO...二氧化碳(CO_(2))是主要的温室气体,但同时也是一种储量巨大、廉价、安全且易得的可再生资源。在我国“碳达峰、碳中和”战略目标的驱动下,如何有效减少CO_(2)排放并转而利用这一重要碳资源已成为当前的研究热点与重点,这同时也加快了CO_(2)捕集、利用与封存(carbon capture,utilization and storage,CCUS)技术的发展和创新。生物转化是实现CO_(2)利用的主要路径之一,既能够直接催化、转化CO_(2)合成目标产物,也可以与化学催化路径相耦合实现对CO_(2)来源的有机低碳资源(如甲醇、甲酸、乙酸)的有效转化及定向合成,因此有望在国家“双碳”目标的实现中发挥重要作用。本文对近年来CO_(2)生物转化的研究进展进行了梳理和总结,指出了现有技术路线的特点和不足,并对今后的研究重点和方向提出了建议。总体而言,CO_(2)生物利用技术目前尚处于起步阶段。基于化能自养细菌的合成气(CO_(2)/CO)发酵生产乙醇虽已实现工业化,但仍需要进一步优化和提高CO_(2)的转化利用效率,并获得除乙醇外更多的高值产品,从而提升整个技术路线的经济性。而其他的CO_(2)生物转化路径,无论是化学-生物发酵耦合还是体外酶催化,目前离大规模应用还有较大距离,需要进一步优化技术体系和降低成本来满足工业化需求。展开更多
Neodymium(Nd)-based catalyst in butadiene(Bd)polymerization has drawn interests due to its availability in affording higher cis-1,4-unit selectivity than transition metal(Ti,Co,Ni,etc.)-based catalysts[1-2].Such outst...Neodymium(Nd)-based catalyst in butadiene(Bd)polymerization has drawn interests due to its availability in affording higher cis-1,4-unit selectivity than transition metal(Ti,Co,Ni,etc.)-based catalysts[1-2].Such outstanding high cis-1,4-unit selecti-vity is hypothetically originated from the presence of 4 f orbitals,that can participate in monomer coordination and thereby govern subsequent enchainment manners.This unique characteristic also renders the active species highly susceptible to Lewis bases,and may impact the overall selectivity as well as polyme-rization behavior after coordination.Nevertheless,it is still a virgin area in such a field,and the influence of Lewis bases on Nd-based diene polymerizations is still a black box.Based on this consideration,how nitrogen-containing donors(D)impacts the overall behaviors of Nd-mediated Bd polymerizations is disclosed.展开更多
The performance of UV/H_2O_2, UV/O_3, and UV/H_2O_2/O_3 oxidationsystems for the treatment of municipal solid-waste landfill leachatewas investigated. Main objective of the experiment was to removetotal organic carbon...The performance of UV/H_2O_2, UV/O_3, and UV/H_2O_2/O_3 oxidationsystems for the treatment of municipal solid-waste landfill leachatewas investigated. Main objective of the experiment was to removetotal organic carbon (TOC), non-biodegradable organic compounds(NBDOC) and color. In UV/H_2O_2 oxidation experiment, with theincrease of H_2O_2 dosage, removal efficiencies of TOC and coloralong with the ratio of biochemical oxygen demand (BOD) to chemicaloxygen demand (COD) of the effluent were increased and a betterperformance was obtained than the system H_2O_2 alone.展开更多
文摘二氧化碳(CO_(2))是主要的温室气体,但同时也是一种储量巨大、廉价、安全且易得的可再生资源。在我国“碳达峰、碳中和”战略目标的驱动下,如何有效减少CO_(2)排放并转而利用这一重要碳资源已成为当前的研究热点与重点,这同时也加快了CO_(2)捕集、利用与封存(carbon capture,utilization and storage,CCUS)技术的发展和创新。生物转化是实现CO_(2)利用的主要路径之一,既能够直接催化、转化CO_(2)合成目标产物,也可以与化学催化路径相耦合实现对CO_(2)来源的有机低碳资源(如甲醇、甲酸、乙酸)的有效转化及定向合成,因此有望在国家“双碳”目标的实现中发挥重要作用。本文对近年来CO_(2)生物转化的研究进展进行了梳理和总结,指出了现有技术路线的特点和不足,并对今后的研究重点和方向提出了建议。总体而言,CO_(2)生物利用技术目前尚处于起步阶段。基于化能自养细菌的合成气(CO_(2)/CO)发酵生产乙醇虽已实现工业化,但仍需要进一步优化和提高CO_(2)的转化利用效率,并获得除乙醇外更多的高值产品,从而提升整个技术路线的经济性。而其他的CO_(2)生物转化路径,无论是化学-生物发酵耦合还是体外酶催化,目前离大规模应用还有较大距离,需要进一步优化技术体系和降低成本来满足工业化需求。
基金Supported by PetroChina Company Limited Project (2020 B-2711)。
文摘Neodymium(Nd)-based catalyst in butadiene(Bd)polymerization has drawn interests due to its availability in affording higher cis-1,4-unit selectivity than transition metal(Ti,Co,Ni,etc.)-based catalysts[1-2].Such outstanding high cis-1,4-unit selecti-vity is hypothetically originated from the presence of 4 f orbitals,that can participate in monomer coordination and thereby govern subsequent enchainment manners.This unique characteristic also renders the active species highly susceptible to Lewis bases,and may impact the overall selectivity as well as polyme-rization behavior after coordination.Nevertheless,it is still a virgin area in such a field,and the influence of Lewis bases on Nd-based diene polymerizations is still a black box.Based on this consideration,how nitrogen-containing donors(D)impacts the overall behaviors of Nd-mediated Bd polymerizations is disclosed.
文摘The performance of UV/H_2O_2, UV/O_3, and UV/H_2O_2/O_3 oxidationsystems for the treatment of municipal solid-waste landfill leachatewas investigated. Main objective of the experiment was to removetotal organic carbon (TOC), non-biodegradable organic compounds(NBDOC) and color. In UV/H_2O_2 oxidation experiment, with theincrease of H_2O_2 dosage, removal efficiencies of TOC and coloralong with the ratio of biochemical oxygen demand (BOD) to chemicaloxygen demand (COD) of the effluent were increased and a betterperformance was obtained than the system H_2O_2 alone.
