We introduce a straightforward method for the preparation of novel starch‐based ultramicroporous carbons (SCs) that demonstrate high CH₄ uptake and excellent CH₄/N₂ selectivity. These SCs are derived from a combination of starch and 1–6 wt.% of acrylic acid, and the resulting materials are amenable to surface cation exchangeability as demonstrated by the formation of highly dispersed K⁺ in carbon precursors. Following activation, these SCs contain ultramicropores with narrow pore‐size distributions of <0.7 nm, leading to porous carbon‐rich materials that exhibit CH₄ uptake values as high as 1.86 mmol/g at 100 kPa and 298 K, the highest uptake value for CH₄ to date, with the IAST‐predicted CH₄/N₂ selectivity up to 5.7. Both the potential mechanism for the formation of the narrow pores and the origin of the favorable CH₄ adsorption properties are discussed and examined. This work may potentially guide future designs for carbon‐rich materials with excellent gas adsorption properties.

中文翻译：

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通过原位离子活化轻松合成具有超高CH4吸收量的超微孔碳吸附剂

我们介绍了一种简单的方法来制备新型的基于淀粉的超微孔碳（SC），这些碳具有很高的CH ₄吸收率和出色的CH ₄ / N ₂选择性。这些SC衍生自淀粉和1-6％（重量）的丙烯酸的组合，所得材料具有表面阳离子交换性，如在碳前体中高度分散的K ⁺的形成所证明。激活后，这些SC包含孔径小于0.7 nm的超微孔，导致富含碳的多孔材料在100 kPa和298 K时表现出高达1.86 mmol / g的CH ₄吸收值，是CH ₄的最高吸收值。通道₄迄今为止，IAST预测的CH ₄ / N ₂选择性高达5.7。讨论并研究了形成细孔的潜在机理和有利的CH ₄吸附特性的起源。这项工作可能会为气体吸附性能优异的富碳材料的未来设计提供指导。