Alkali activation was the common method to prepare commercial porous carbon. In a mixed alkali activation system, the role of individual alkali was generally assumed to be the same as in single alkali activation system, and only low corrosiveness of weak alkali was mostly emphasized. However, the intrinsic roles of individual alkali should be finely understanded and redefined to illuminate the activation pathway from the perspective of internal chemical reactions rather than corrosiveness. Herein, combing the in situ TG-MS analysis, DFT calculation and other characterizations, the activation processes were precisely tracked and the activation pathways were proposed. In the mixed alkali activation system, the strong alkali KOH served as the activation promoter, first decomposing into K₂O, which then attacks the C-C bonds, forming active reaction sites defined as pore seeds. The weak alkali K₂CO₃ acted as the activation pathway modifier, CO₃²⁻ preferentially etched the pore seeds over K₂O due to the lower reaction barrier of CO₃²⁻ interacting with the pore seeds. Consequently, the rough etching reaction of KOH was replaced and suppressed by the gentler action of CO₃²⁻ forming more micropores. When the ratio of strong to weak alkali was 1:1, the obtained CK₁K₂-122 owned the highest microporosity (82.61%) and large specific surface area (1962.18 m² g^-1). It exhibited high specific capacitance of 296.7 F g^-1 and excellent cycling stability with 98.3% retention after 10,000 cycles. The supercapacitor demonstrated high energy density of 114.4 Wh kg^-1 at power density of 17.5 kW kg^-1, with a broad potential window of 3.5 V.

中文翻译：

---

重新定义碱活化剂在多孔碳中的作用


碱活化是制备商业多孔碳的常用方法。在混合碱活化体系中，一般假设单个碱的作用与在单一碱活化体系中的作用相同，只强调弱碱的低腐蚀性。然而，应精细理解和重新定义单个碱的内在作用，以便从内部化学反应而不是腐蚀性的角度阐明活化途径。本文结合原位 TG-MS 分析、DFT 计算等表征，精确跟踪活化过程并提出活化途径。在混碱活化体系中，强碱 KOH 作为活化促进剂，首先分解成 K₂O，然后攻击 C-C 键，形成定义为孔种子的活性反应位点。弱碱 K₂CO₃ 作为激活途径修饰剂，由于 CO₃²⁻ 与孔种子相互作用的反应势垒较低，因此 CO₃²⁻ 优先蚀刻孔种子而不是 K₂O。因此，KOH 的粗蚀反应被 CO₃²⁻ 的更温和作用所取代和抑制，从而形成更多的微孔。当强碱与弱碱比为1：1时，所得的CK₁K2-122具有最高的微孔率（82.61%）和较大的比表面积（1962.18 m^{2 g-1}）。它表现出 296.7 F ^g-1 的高比电容和 98 的出色循环稳定性。10,000 次循环后保留率为 3%。超级电容器在 17.5 kW ^kg-1 的功率密度下表现出 114.4 Wh ^kg-1 的高能量密度，具有 3.5 V 的宽电位窗口。