The Reaction Mechanisms of H2S Decomposition into Hydrogen and Sulfur: Application of Classical and Biological Thermodynamics
The Reaction Mechanisms of H2S Decomposition into Hydrogen and Sulfur: Application of Classical and Biological Thermodynamics
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H2S分解为氢和硫的反应机理：经典和生物热力学的应用
DOI：
10.4172/2157-7544.1000186
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
Startsev An
中科院分区：
文献类型：
--
作者：
Startsev An
H2S分解为氢和元素硫的四种可能途径被认为是。在热可逆过程中，根据自旋守恒规则，H2S解离导致形成单重态的双原子氢和硫：
（一）
在硫化物催化剂的表面上，不可逆的H2S裂解在低温下通过二硫烷阶段进行，H2 S2形成为关键的表面中间体，随后由于氢气释放到气相中而分解，并且吸附的单线态硫重新结合成环八硫：
（二）
在金属催化剂上，不可逆的H2S分解在低温下发生，通过H2S解离成吸附的原子表面物质的阶段，导致形成处于基态电子态的两种双原子反应产物-单线态氢和三线态双原子硫：
（三）
反应（ii）和（iii）被认为是在生物热力学原理下实现的，在不存在催化剂的情况下，这两种反应在气相中被化学地禁止。硫细菌同化H2S的机制被认为发生在化学合成过程中，导致无色硫球和活性氢的形成：
（四）
类似于细菌过程，在能够良好溶解H2S的液体中浸渍金属催化剂，实现了从H2S制氢，效率为99.6%。
Four possible pathways of H2S decomposition into hydrogen and elemental sulfur are considered. In the thermal reversible process, H2S dissociation results in the formation of diatomic both hydrogen and sulfur in the singlet state according to the rule of spin conservation:
(i)
On the surface of sulfide catalysts, irreversible H2S splitting proceeds at low temperature through the stage of disulfane, H2S2 formation as a key surface intermediate, followed by its decomposition due to release of hydrogen into the gas phase and recombination of the adsorbed singlet sulfur into cyclooctasulfur:
(ii)
On metal catalysts, irreversible H2S decomposition occurs at low temperature through the stage of H2S dissociation into the adsorbed atomic surface species resulted in the formation of both diatomic reaction products in the ground electronic state -the singlet hydrogen and the triplet diatomic sulfur:
(iii)
The reactions (ii) and (iii) are considered to be realized under the principles of biological thermodynamics, in the absence of catalyst both reactions are thermodynamically prohibited in the gas phase. The mechanism of H2S assimilation by sulfur bacteria is suggested to occur in the processes of chemosynthesis resulted in the formation of colorless sulfur globules and activated hydrogen:
(iv)
Similar to the bacterial process, the hydrogen production from H2S is realized with the efficiency of 99.6% on metal catalysts immersed into the liquid which is capable well-dissolving H2S.