析氫反應在Fe2O3、FeP、Co3O4、Co2P及其相關衍生物的理論計算研究

Abstract

析氫反應(HER)是用於高效生產純淨氫燃料的重要催化製程。我們目前的工作通過計算研究了更便宜和常用的Fe2O3、FeP、Co3O4、Co2P催化劑及其衍生物的HER，包括摻雜P和Co的Fe2O3、摻雜O和Co的FeP、摻雜P和Fe的Co3O4 以及摻雜O和Fe的Co2P。已經徹底計算了氫原子吸附的吸附能E_ads (H^*)和吉布斯自由能∆G(H^*)的能量以檢查HER活性，且分析了這些催化劑的態密度(DOS)與能帶中心，進而合理化能量結果。能量結果最初表明Fe2O3(116)、FeP(121)、Co3O4(222)與Co2P(100)是這些未摻雜催化劑中HER活性最好的晶面。此外，它們的相對HER活性遵循FeP> Co2P > Co3O4 > Fe2O3的順序。將O摻雜到FeP (O-FeP)可以進一步提高活性，而將P摻雜到Fe2O3(P-Fe2O3)會降低活性。將P摻雜到Co3O4 (P-Co3O4)可以進一步提高活性，而將O摻雜到Co2P (O-Co2P)會降低活性。它們的相對HER活性遵循O-FeP > P-Co3O4 > O-Co2P > P-Fe2O3。摻雜金屬的製程可以在一定程度上提高活性，其HER活性順序為Co-FeP > Fe-Co2P > Co-Fe2O3 > Fe-Co3O4。最後，我們的結果得出結論，O-FeP有望在所有這些催化劑中表現出最佳的HER活性。

Hydrogen evolution reaction (HER) is an important catalytic process utilizing for the efficient production of clean hydrogen fuels. Our present work computationally investigates HER on the cheaper and commonly used catalysts of Fe2O3, FeP, Co3O4, Co2P and their deviates, including P and Co-doped Fe2O3, O and Co-doped FeP, P and Fe-doped Co3O4 and O and Fe-doped Co2P. The energetics of adsorption energy, E_ads (H^*), and Gibbs free energy, ∆G(H^* ) for atomic hydrogen adsorption have been thoroughly computed to examine the HER activity; the density of state (DOS) and band centers of those catalysts have been analyzed to rationalize the energetic results. The energetic results initially find that Fe2O3(116), FeP(121), Co3O4(222) and Co2P(100) are the best facets among those un-doped catalysts. Also, their relative HER activity follows the order of FeP> Co2P > Co3O4 > Fe2O3. Doping O to FeP (O-FeP) can further improve the activity, while doping P to Fe2O3 (P-Fe2O3) causes deactivation. Doping P to Co3O4 (P-Co3O4) can further improve the activity, while doping O to Co2P (O-Co2P) causes deactivation. Their relative HER activity follows the order of O-FeP > P-Co3O4 > O-Co2P > P-Fe2O3. The metallic doping process can somewhat promote the activity and their order follows Co-FeP > Fe-Co2P > Co-Fe2O3 > Fe-Co3O4. Finally, our results conclude that O-FeP is expected to show the best HER activity among all those catalysts.