Knoche Gupta Krysti L, Lee Heung Chan, Leddy Johna
Department of Chemistry, University of Iowa, Iowa City, Iowa 52240, United States.
ACS Phys Chem Au. 2024 Jan 3;4(2):148-159. doi: 10.1021/acsphyschemau.3c00039. eCollection 2024 Mar 27.
Hydrogen evolution reaction (HER) rates are higher where magnetic gradients are established at electrode surfaces. In comparison of literature data for metals with comparable work functions, we note 1000× higher rates for paramagnetic metals than diamagnetic metals. With unpaired electron spins, paramagnetic and ferromagnetic metals establish interfacial magnetic gradients. At diamagnetic electrodes, gradients are induced by addition of magnetized microparticles. Onset of hydrogen evolution for magnetized γ-FeO microparticles in Nafion on diamagnetic glassy carbon electrodes is lower by 190 mV (-18 kJ mol) relative to demagnetized microparticles. Chemically the same as demagnetized particles, the physical distinction of magnetic field and gradient at magnetized microparticles increases electron transfer rate. For magnetized FeO microparticles, the onset is lower by 280 mV (-27 kJ mol). Paramagnetic platinum electrodes are unaffected by addition of magnetized microparticles. Magnetoelectrocatalysis is established by magnetic gradients.
在电极表面建立磁梯度的地方，析氢反应（HER）速率更高。在比较具有可比功函数的金属的文献数据时，我们注意到顺磁性金属的速率比抗磁性金属高1000倍。由于具有未成对电子自旋，顺磁性和铁磁性金属会建立界面磁梯度。在抗磁性电极上，通过添加磁化微粒来诱导梯度。相对于去磁微粒，在抗磁性玻碳电极上的Nafion中，磁化的γ-FeO微粒的析氢起始电位降低了190 mV（-18 kJ/mol）。与去磁微粒在化学上相同，磁化微粒处磁场和梯度的物理差异增加了电子转移速率。对于磁化的FeO微粒，起始电位降低了280 mV（-27 kJ/mol）。顺磁性铂电极不受添加磁化微粒的影响。磁电催化是由磁梯度建立的。
