Andrade Samantha K Samaniego, Bakos István, Dobos Gábor, Farkas Attila, Kiss Gábor, Klébert Szilvia, Madarász János, László Krisztina
Department of Physical Chemistry and Materials Science, Budapest University of Technology and Economics, 1521 Budapest, Hungary.
Research Centre for Natural Sciences, Institute of Materials and Environmental Chemistry, Eötvös Loránd Research Network, Magyar tudósok körútja 2, 1117 Budapest, Hungary.
Materials (Basel). 2021 Jun 23;14(13):3488. doi: 10.3390/ma14133488.
In this paper we report the synthesis of a N, S co-doped metal free carbon cryogel obtained from a marine biomass derived precursor using urea as nitrogen source. Natural carrageenan intrinsically contains S and inorganic salt. The latter also serves as an activating agent during the pyrolytic step. The overall 11.6 atomic % surface heteroatom concentration comprises 5% O, 4.6% N and 1% S. The purified and annealed final carbon (CA) has a hierarchical pore structure of micro-, meso- and macropores with an apparent surface area of 1070 m/g. No further treatment was applied. The gas adsorption potential of the samples was probed with H, CO and CH, while the electrocatalytic properties were tested in an oxygen reduction reaction. The atmospheric CO and CH storage capacity at 0 °C in the low pressure range is very similar to that of HKUST-1, with the CO/CH selectivity below 20 bar, even exceeding that of the MOF, indicating the potential of CA in biogas separation. The electrocatalytic behavior was assessed in an aqueous KOH medium. The observed specific gravimetric capacitance 377 F/g was exceeded only in B, N dual doped and/or graphene doped carbons from among metal free electrode materials. The CA electrode displays almost the same performance as a commercial 20 wt% Pt/C electrode. The oxygen reduction reaction (ORR) exhibits the 4-electron mechanism. The 500-cycle preliminary stability test showed only a slight increase of the surface charge.
在本文中，我们报道了一种由海洋生物质衍生前驱体，使用尿素作为氮源合成的氮、硫共掺杂无金属碳气凝胶。天然卡拉胶本身含有硫和无机盐。后者在热解步骤中也用作活化剂。总的表面杂原子浓度为11.6原子%，其中包括5%的氧、4.6%的氮和1%的硫。纯化并退火后的最终碳材料（CA）具有由微孔、中孔和大孔组成的分级孔结构，表观表面积为1070 m²/g。未进行进一步处理。用氢气、一氧化碳和甲烷探测了样品的气体吸附潜力，同时在氧还原反应中测试了其电催化性能。在0°C的低压范围内，大气中一氧化碳和甲烷的储存容量与HKUST-1非常相似，在20巴以下的一氧化碳/甲烷选择性甚至超过了金属有机框架材料（MOF），表明CA在沼气分离方面的潜力。在氢氧化钾水溶液介质中评估了电催化行为。在无金属电极材料中，仅硼、氮双掺杂和/或石墨烯掺杂的碳材料的比电容超过了所观察到的377 F/g的比电容。CA电极的性能几乎与商业20 wt%的铂碳电极相同。氧还原反应（ORR）呈现4电子机制。500次循环的初步稳定性测试表明表面电荷仅略有增加。
