Abstract The functionality of biochar surfaces depends on the nature of the feedstock, pyrolysis temperature, and residence time. In this study, molecular modeling was used to determine the types of functionalization that could enhance adsorption and to pre-screen the target adsorbate for the sake of minimizing experimental time. The impact of a single functional group and interaction between them (including nitrile, methyl, ether, furan, carboxyl, hydroxyl, amine, and amide) on the adsorption of target adsorbate onto biochar was investigated. Among biochars inherent functional groups simulated, the lowest energy of adsorption (highest adsorption) occurred with carboxyl and hydroxyl for CO2 adsorption due to hydrogen bonding. The simulations showed adding amine/amide functional groups to the biochar surface enhanced CO2 adsorption, because of stronger bonding. The simulation results were compared against experimental results and the thermodynamic properties were satisfactorily matched. The overall heat of adsorption of H2S was lower than CO2, but the average Gibbs free energy was approximately the same, indicating CO2 could replace H2S in initial screening adsorption experiments for this type of biochar, reducing costs, risk and toxicity concerns of using H2S. This is an example of potentially how the models can be used to better design experiments.

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生物炭表面异质性和氮功能化的研究：分子建模方法

摘要 生物炭表面的功能取决于原料的性质、热解温度和停留时间。在这项研究中，分子模型用于确定可以增强吸附的功能化类型并预筛选目标吸附物，以最大限度地减少实验时间。研究了单个官能团和它们之间的相互作用（包括腈、甲基、醚、呋喃、羧基、羟基、胺和酰胺）对目标吸附物在生物炭上吸附的影响。在模拟的生物炭固有官能团中，由于氢键作用，羧基和羟基对 CO2 的吸附能量最低（吸附量最高）。模拟表明在生物炭表面添加胺/酰胺官能团增强了 CO2 吸附，因为结合力更强。将模拟结果与实验结果进行了比较，热力学性质匹配良好。H2S 的整体吸附热低于 CO2，但平均吉布斯自由能大致相同，表明 CO2 可以在此类生物炭的初步筛选吸附实验中替代 H2S，降低使用 H2S 的成本、风险和毒性问题。这是一个可能如何使用模型来更好地设计实验的示例。表明 CO2 可以在此类生物炭的初步筛选吸附实验中替代 H2S，从而降低使用 H2S 的成本、风险和毒性问题。这是一个可能如何使用模型来更好地设计实验的示例。表明 CO2 可以在此类生物炭的初步筛选吸附实验中替代 H2S，从而降低使用 H2S 的成本、风险和毒性问题。这是一个可能如何使用模型来更好地设计实验的示例。