（图片仅供参考）
Catalysis is the process of increasing the rate of a chemical reaction by adding a substance known as a 催化剂. Catalysts are not consumed in the reaction and remain unchanged. They work by providing an alternative reaction pathway with a lower activation energy ([latex]E_a[/latex]), thereby accelerating both the forward and reverse reactions without altering the overall thermodynamics ([latex]\Delta H[/latex]).
The fundamental principle of catalysis lies in its ability to alter the kinetics of a chemical reaction without affecting its thermodynamics. A 催化剂 introduces a new reaction mechanism, often involving one or more intermediate steps. For a reaction A + B → C, a catalyst C’ might participate as follows: A + C’ → AC’ and then AC’ + B → C + C’. The catalyst C’ is regenerated at the end of the process. This alternative pathway has a lower transition state energy compared to the uncatalyzed reaction. The Arrhenius equation, [latex]k = Ae^{-E_a/(RT)}[/latex], shows that a lower activation energy ([latex]E_a[/latex]) leads to an exponential increase in the reaction rate constant (k). Importantly, the catalyst does not change the Gibbs free energy change ([latex]\Delta G[/latex]) or the equilibrium constant ([latex]K_{eq}[/latex]) of the reaction. It only affects the speed at which equilibrium is reached. This concept was first formally described by Jöns Jacob Berzelius in 1835, who observed that certain substances could accelerate reactions without being consumed, coining the term “catalysis” from Greek words meaning “to dissolve” or “to break down”.
这一原理可以通过反应坐标图直观地展现出来，其中催化途径的能量峰（过渡态）低于非催化途径。虽然反应物和产物之间的总能量差保持不变，但需要克服的能垒显著降低。这使得更大比例的反应物分子在碰撞时拥有足够的能量进行反应，从而在给定温度下实现更快的反应速率。
催化
（如果日期未知或不相关，例如“流体力学”，则提供其显著出现的近似估计）
只有注册会员才能免费获得 100% 的全尺寸图片和下载。.
> 登录 <
