Synthesis of Co3 O4 /Carbon Heteroaerogels with Ultrahigh Capacitance via Polyethyleneimine Intercalation of Co2 BIM4 Nanosheets.

The development of metal-organic frameworks (MOFs)-based supercapacitors have attracted intense concentration in recent years due to their regularly arranged porous and tunable pore sizes. However, the performance of the MOFs-derived supercapacitors is also low because of their poor electrical conductivity and rarely accessible active sites. In the present work, we developed a Co-MOF (namely Co2 BIM4 , BIM=benzimidazole) nanosheets derived Co3 O4 /nitrogen-doped carbon (Co2 BIM4 -Co3 O4 /NC) heteroaerogel as a novel supercapacitor electrode. The 3D Co2 BIM4 -Co3 O4 /NC heteroaerogels were obtained by directly intercalating polyethyleneimine (PEI) into the interlayers of Co2 BIM4 nanosheets and following by carbonizing the resulting Co2 BIM4 /PEI composite. The Co2 BIM4 -Co3 O4 /NC electrode possessed 3D conductive framework with an overlapped hetero-interface and expanded interlayers, leading to fast and stable charge transfer/diffusion and an enhanced pseudocapacitance performance. Therefore, the Co2 BIM4 -Co3 O4 /NC electrode showed ultrahigh capacitance of 2568 F g-1 at 1 A g-1 , 1747 F g-1 at 10 A g-1 , and excellent long cycling time with a capacitance preservation of 92.7 % following 10000 cycles at 10 A g-1 , which is very promising for applications in supercapacitors and other energy storage devices.

Highly Selective CO2 Conversion to Methanol in a Bifunctional Zeolite Catalytic Membrane Reactor.

The hydrogenation of sequestrated CO2 to methanol can reduce CO2 emission and establish a sustainable carbon circuit. However, the transformation of CO2 into methanol is challenging because of the thermodynamic equilibrium limitation and the deactivation of catalysts by water. In the present work, different reactor types have been evaluated for CO2 catalytic hydrogenation to methanol. Best results have been obtained in a bifunctional catalytic membrane reactor (CMR) based on a zeolite LTA membrane and a catalytic Cu-ZnO-Al2 O3 -ZrO2 layer on top. Due to the in situ and rapid removal of the produced water from the catalytic layer through the hydrophilic zeolite LTA membrane, it is effective to break the thermodynamic equilibrium limitation, thus significantly increasing the CO2 conversion (36.1 %) and methanol selectivity (100 %). Further, the catalyst deactivation by the produced water can be effectively inhibited, thus maintaining a high long-term activity of the CMR.