In this work, we report a facile, solvent-free, and one-step route for the fabrication of N-doped carbon by employing low-cost raw materials (i.e., alginic acid and ammonium chloride), which can serve as a high-efficiency metal-free catalyst for the reduction of 4-nitrophenol (4-NP). The as-prepared catalyst possesses high nitrogen content (up to 5.49 at %), high specific surface area (up to 630 m²·g^-1), and abundant defects, making it possible to provide sufficient active sites for the reduction of 4-NP. The excellent catalytic performance with high apparent rate constant (0.2141 min^-1) and TOF value (1.33×10^-4 mmol∙mg^-1∙min^-1), matches or even exceeds that of most reported metal-based catalysts. Density functional theory (DFT) calculations reveal that this excellent catalytic activity can be achieved via tuning the electron transfer and promoting the adsorption of 4-NP ions by introducing N atoms. The kinetic and thermodynamic parameters of the reaction were explored in detail, fitting well to the Langmuir-Hinshelwood model. This work not only proposes a versatile strategy to prepare advanced N-doped carbon materials but also provides useful guidance for designing and developing biomass-derived metal-free catalysts for various catalytic reactions.

在这项工作中，我们报告了通过使用低成本原材料（例如藻酸和氯化铵）制造N掺杂碳的简便，一步一步的方法，该材料可以用作用于还原4-硝基苯酚（4-NP）的高效无金属催化剂。所制备的催化剂具有高的氮含量（高达5.49  at％），高的比表面积（高达630 m ² ·g ^-1）和大量的缺陷，从而有可能提供足够的活性位点来还原4 -NP。优异的催化性能，表观速率常数（0.2141  min ^-1）和TOF值（1.33×10 ^-4  mmol∙mg ^-1 ∙min ^-1），甚至达到甚至超过大多数报道的金属基催化剂的水平。密度泛函理论（DFT）计算表明，可以通过调节电子传递并通过引入N原子来促进4-NP离子的吸附来实现这种出色的催化活性。详细探讨了反应的动力学和热力学参数，非常适合Langmuir-Hinshelwood模型。这项工作不仅提出了一种制备先进的N掺杂碳材料的通用策略，而且还为设计和开发用于各种催化反应的生物质衍生的无金属催化剂提供了有用的指导。