In this work, N-doped porous carbons were synthesized by a one-step sodium amide activation of carbonized lotus leaf at 450–500 °C. The CO2 adsorption properties of the as-synthesized carbonaceous materials were carefully investigated. In addition, the supercapacitor performance of the optimized sample was also preliminarily explored to examine its potential as the electrode material. These lotus leaf-derived carbons possess good CO2 adsorption capacity up to 3.50 and 5.18 mmol/g at 25 and 0 °C under atmospheric pressure, respectively. It was found that the synthetic effects of narrow microporosity, N content, pore size, and pore size distribution of the sorbents decide their CO2 adsorption abilities under the ambient conditions. These lotus leaf-based carbons also demonstrate many excellent CO2 adsorption properties, such as good selectivity of CO2 over N2, quick adsorption kinetics, moderate heat of adsorption, excellent recyclability, and high dynamic adsorption capacity. In addition, preliminary electrochemical studies show that the optimized sample has high capacitance (266 F/g) and excellent stability in cycling tests. These results indicate these lotus leaf-derived N-doped porous carbons have good potential in the application of CO2 capture and supercapacitor.

In this work, porous carbons were achieved from sustainable biomass lotus stalk. Unlike the common carbonization-activation two-step method, a facile one-step KOH activation procedure was explored to make the carbonaceous sorbents. The as-made adsorbents have advanced porous structures and hold superior CO 2 uptake, up to 3.68 and 5.11 mmol/g at 1 bar, 25 and 0 °C, respectively. After carefully checking the relationship of CO 2 uptake with each porous characteristic, the volume of narrow micropores is found to be the leading factor that determines the CO 2 adsorption abilities of the adsorbents under ambient conditions. Moreover, the narrower pore size distribution is also preferential to the adsorption of CO 2 . Apart from the high CO 2 uptake, these lotus stalk-derived adsorbents also possess extra excellent CO 2 capture properties such as good recyclability, fast adsorption kinetics, reasonable CO 2 /N 2 selectivity, suitable heat of adsorption, and high dynamic adsorption capacity. These results demonstrate that these cost-effective carbonaceous adsorbents developed by the facile one-step method have potential in the application of actual CO 2 capture.

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In this work, highly efficient nitrogen-doped porous carbonaceous CO2 sorbents were synthesized by sodium amide activation of petroleum coke at a temperature range of 400–500 °C. The as-obtained sorbents exhibit an excellent CO2 uptake of 3.84 mmol/g (25 °C) and 5.93 mmol/g (0 °C) under atmospheric pressure. It is found that in addition to the two well-accepted factors, i.e., narrow micropore volume and nitrogen content, the pore size and pore size distribution also exhibit important effects on CO2 uptake under ambient condition for these adsorbents. Furthermore, these petroleum-coke-derived nitrogen-enriched carbonaceous sorbents also exhibit other merits such as high selectivity of CO2 over N2, excellent recyclability, fast adsorption kinetics, suitable heat of adsorption, and excellent dynamic CO2 uptake. This paper offers additional insight and useful information in preparing highly efficient nitrogen-doped porous carbonaceous CO2 adsorbents.

High-temperature proton exchange membrane fuel cells (HT-PEMFCs) are crucial in future energy systems. However, the activity and stability of the electrocatalysts are severely restricted by high temperature and phosphoric acid poisoning. Herein, PtCe alloy as oxygen reduction reaction (ORR) electrocatalyst for HT-PEMFCs exhibits fantastic performance. Ce can increase the electronic density of Pt, weakening phosphoric acid poisoning and improving ORR activity. The optimized electronic structure can also reduce the dipole effect between Pt and O, which suppresses the irreversible oxidation of Pt. Additionally, the dramatically negative heat of formation in PtCe catalyst brings high kinetic barrier of metal diffusion and dissolution. With this electrocatalyst, the HT-PEMFCs show a preeminent peak power of 605 mW cm À 2 with 0.3 mg Pt cm À 2 . After 30000 cycles of accelerated stability test, the peak power density only decreases by 31.6%, achieving the goal of Department of Energy in 2020 (< 40% loss).