This work investigates the development of metal incorporated biochar as a low-cost and robust adsorbent for high capacity CO₂ capture at ambient condition. For this purpose, biochars were prepared through single-step pyrolysis of walnut shell (WS) at different temperatures (500, 700 and 900 °C). The biochar with larger specific surface area and higher microporosity fraction (WS900) was then subjected to metal impregnation followed by N₂ heat treatment. The incorporation of basic metal sites into the biochar skeleton enhanced the adsorption of acidic CO₂ gas onto the metalized-biochar in the sequence of Mg > Al > Fe > Ni > Ca > raw-biochar > Na. The enhanced CO₂ uptake of Mg-loaded biochar (82.0 mg/g) compared to the pristine biochar (72.6 mg/g) at 25 °C and 1 atm, could be explained by the synergistic effects of physical and chemical interactions, yet kinetic studies showed that physisorption was the main governing mechanism controlling the adsorption of CO₂ onto the metalized-biochar. Cyclic CO₂ capture studies indicated the great stability of Mg-loaded biochar upon several cycles of adsorption-desorption, with no loss in its CO₂ capture capacity. It also showed easy regeneration and fast desorption kinetic which makes it a promising inexpensive candidate for real-world CO₂ capture systems. Moreover, the adsorbent showed a superior capture performance towards CO₂ over N₂, O₂ and CH₄.

这项工作研究了掺入金属的生物炭作为一种低成本，坚固的吸附剂在环境条件下捕获高容量CO _2的开发。为此，通过在不同温度（500、700和900°C）下对核桃壳（WS）进行单步热解来制备生物炭。然后，将具有较大的比表面积和较高的微孔率（WS900）的生物炭进行金属浸渍，然后进行N ₂热处理。碱性金属位点进入生物炭骨架中增强了酸性CO ₂气体在金属化生物炭上的吸附顺序，依次为Mg> Al> Fe> Ni> Ca>原始生物炭> Na。增强的CO ₂在25°C和1个大气压下，与原始生物炭（72.6 mg / g）相比，载有Mg的生物炭（82.0 mg / g）的吸收可以通过物理和化学相互作用的协同作用来解释，但动力学研究表明，物理吸附是控制CO ₂在金属化生物炭上的吸附的主要控制机制。循环CO ₂捕集研究表明，在几个吸附-解吸循环后，负载镁的生物炭具有很大的稳定性，而其CO ₂捕集能力没有损失。它还显示出容易的再生和快速的解吸动力学，这使其成为现实世界中CO ₂捕集系统的有希望的廉价候选者。此外，该吸附剂对CO _2的捕获性能优异。在N ₂，O ₂和CH _4上。