本研究開發一新型電催化觸媒，可應用於電化學槽內作為陽極及陰極觸媒，並同時進行氧氣析出(OER)及氧氣還原(ORR)，能有效的產生過氧化氫(H2O2)，其為高單價產品與燃料，並可達到符合經濟效益及儲能的效果，目前於水電解反應的研究又以析氧反應居多，其因為反應緩慢與觸媒活性等問題造成應用上的不便。而目前於ORR中產H2O2的觸媒，多苦於低選擇性與低質量活性等問題，造成現行H2O2生產，仍以傳統式高耗能的蒽醌法(anthraquinone process)合成。因此本研究以非貴金屬鎳鐵層狀雙氫氧化物(NiFe LDH)作為主體，並以鉑氫氧化物(Pt(OH)x)嵌入其層間，藉此提升整體析氧與H2O2選擇性與產量。此觸媒主體對OER與產H2O2反應原始就有一定的活性，並藉由無活性的Pt 進行氧化還原並嵌入來達到提升雙活性的效果。
觸媒的製備方式先以簡便的水熱法合成NiFe LDH，並利用共沉澱法將Pt(OH)x嵌入層狀結構。其中因為想增加Pt(OH)x含量與確認結構穩定，並保持單原子的型態，我們更利用了本實驗室過去曾使用的方法，合成帶負電的Pt(OH)x2-，以利於在室溫下能將其嵌入層間並維持單原子型式，並經測試後得知其在pH13與24hr時有較佳的合成條件。
研究結果顯示， Pt(OH)x以單金屬氫氧化物的方式存在3.25%Pt SA/NiFe LDH觸媒中，使Pt由原始的低活性轉變為高活性位點。其中Pt(OH)x與NiFe LDH上的Ni具有較強的作用力(並無直接鍵結)，造成Ni原子電子雲密度稀缺，使整體H2O2選擇性從87%提升至92%，且質量活性也能從19.23 A/g提升至62.22 A/g，為未嵌入Pt(OH)x時3倍量，於XRD與FTIR分析，能得知Pt(OH)x是以陰離子形態存在於層間，能有效的降低NiFe LDH厚度，並提升活性面積與層間距，且其與SO42-間具有作用力，造成整體活性位增加，且使H2O2選擇性與產量大幅提升，亦能有效提升穩定性。

A new bifunctional electrocatalytic catalyst has been developed for the oxygen-involving energy conversion reactions. It can be used as anode and cathode catalysts in electrochemical cells, and perform oxygen evolution reaction (OER) and oxygen reduction reaction (ORR), where hydrogen peroxide (H2O2) can be effectively produced with potential economic benefits and perspectives in energy storage. Currently, most research activities about water electrolysis reaction are related to oxygen evolution reaction, whose sluggish reaction kinetics and limited activity cause inconvenience in applications. In addition, the electrocatalysts suitable for H2O2 production in ORR usually suffer from low selectivity and low mass activity. The challenges explain why current production of H2O2 still rely on the traditional and energy-intenstive anthraquinone process. Therefore, in this research, the non-precious metal nickel-iron layered double hydroxide (NiFe LDH) was used as the carrier, and platinum hydroxide (Pt(OH)x) was inserted between the layers to improve the overall oxygen evolution reaction and H2O2 selectivity and mass activity. This NiFe LDH catalyst carrier is known for its activity for the oxygen evolution and H2O2 production reactions, and it is hoped that the dual activity can be further enhanced by redox and intercalated inactive Pt.
NiFe LDH was synthesized by a facile hydrothermal method and Pt(OH)x was prepared by a co-precipitation method to intecalate between layered structure. Since Pt(OH)x exists in a state of single-atom/ionic cluster and confirm the stability of the structure, this allows us to increase the content of Pt(OH)x, while maintaining it in the single-atom form. A method previously developed in our laboratory was then applied to synthesize negatively charged Pt(OH)x2- at room temperature for this purpose. It is confirmed that Pt(OH)x2- ions are intercalated between the layers and maintain a singl-atom form. After measuring, the condition of synthesis is found that it has better synthesis conditions at pH 13 and 24 hr.
The research results show that Pt(OH)x exists in the 3.25% Pt SA/NiFe LDH catalyst in the form of single metal hydroxide, which makes Pt change from the original low activity to the high activity site. Among them, the Ni has a strong interaction (no direct bonding) toward Pt(OH)x, so that Ni atom electron cloud density decreased and, the overall H2O2 selectivity of the composite electrocatalyst increases from 87% to 92%, and the mass activity can also be increased from 19.23 A/g to 62.22 A/g, which is 3 times higher than the amount when Pt(OH)x was not embedded. Confirmed by the XRD and FTIR analyses, Pt(OH)x exists in the form of anion between the layers, which can effectively reduce the thickness of NiFe LDH, and increase the active area and layer spacing. It has a force between the anions, resulting in an increase in the overall active sites, and H2O2 selective and the mass activity has been greatly increased, and the stability is also improved.

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