Enhancing Hydrogen Oxidation and Evolution Kinetics by Tuning the Interfacial Hydrogen‐Bonding Environment on Functionalized Platinum Surfaces

Abstract

Developing efficient catalytic systems for the hydrogen oxidation and evolution reactions (HOR/ HER) is essential in the world's transition to renewable energy. There is a growing recognition that the HOR/ HER activity depends on properties of the electrochemical interface, rather than just the composition and structure of the catalyst. Herein, we demonstrate that specifically adsorbed organic additives (theophylline derivatives) could enhance the intrinsic HOR/HER activity in base on polycrystalline Pt by up to a factor of 3 via introducing weakly hydrogen-bonded water, as confirmed by in situ surface enhanced infrared and Raman spectroscopies. Optimal HOR/HER activity is achieved on a 7-n-butyltheophylline decorated Pt surface, which sufficiently disrupts the hydrogen bonding network in the double layer without depleting the interfacial water. This work demonstrates the promise of electrochemical interfacial engineering as a strategy to boost electrocatalytic performance.

Mo‐Modified ZnIn2S4@NiTiO3 S‐Scheme Heterojunction with Enhanced Interfacial Electric Field for Efficient Visible‐Light‐Driven Hydrogen Evolution

“…A contact angle of 60.8° for ZIS nanosheets is bigger than that of Mo 1.4 ‐ZIS matrix (47.5°), suggesting that the latter possesses better surface hydrophilicity and thus adsorbs more water molecules to release sufficient hydrogen proton for reductive hydrogen evolution. [ 53,54 ]…”

“…A contact angle of 60.8° for ZIS nanosheets is bigger than that of Mo 1.4 -ZIS matrix (47.5°), suggesting that the latter possesses better surface hydrophilicity and thus adsorbs more water molecules to release sufficient hydrogen proton for reductive hydrogen evolution. [53,54] Subsequently, the simulation calculations were conducted to gain the electronic properties of Mo-ZIS@NTO catalyst. As the calculated density of state (DOS) depicted in Figure 7d,e, the maximum valence band (VBM) values of ZIS and Mo-ZIS are mainly contributed by sole S-3p orbital, while the conduction band minimum (CBM) for both samples are from In-5s and S-3p orbitals.…”

Boosting Hydrogen Oxidation Kinetics by Promoting Interfacial Water Adsorption on d-p Hybridized Ru Catalysts

“…Furthermore, in situ Raman spectra of Sn-Ru/C show a broad band during the potential region from 0.2 to −0.1 V (Figure c). The broad peak located at around 3200 and 3400 cm –1 can fall to the stretching vibration of O–H in the interfacial water. , With the increase of potential, the centered Raman spectra show blue shift because of the Stark tuning effect of surface-adsorbed species, , verifying stronger interactions between water molecules. As shown in Figures d, S20, and S21, the Stark slopes of different kinds of O–H stretching for Sn-Ru/C (58.8 cm –1 V –1 for tetrahedrally coordinated water, 69.5 cm –1 V –1 for trihedrally coordinated water, and 79.2 cm –1 V –1 for free O–H water, respectively) , are much higher than those of Ru/C (33.2 cm –1 V –1 for tetrahedrally coordinated water, 35.7 cm –1 V –1 for trihedrally coordinated water, and 35.2 cm –1 V –1 for free O–H water, respectively), further illustrating much stronger adsorption of interfacial water on the surface of Sn-Ru/C.…”

“…On the grounds of well-established volcano plots between exchange current densities and the strength of adsorbed hydrogen, the optimal acidic HOR electrocatalysts are expected to possess optimal hydrogen binding energy (HBE) with values close to zero. , However, the kinetics of HOR is much slower in alkaline media. , It was found that the interfacial water molecules on the surface of catalysts could shuffle the HOR intermediates, which is essential for alkaline HOR electrocatalysis. − For example, Xu and co-workers demonstrated that the pH-dependent shift of the oxidation peak of underpotential deposited hydrogen (H upd ) is derived from the adsorption ability and structure of interfacial water on the Pt surface . Very recently, Duan and colleagues deciphered that the hydration layer isolated cations can promote the alkaline HOR activity with the aid of water molecules through tuning the adsorption of reaction intermediates on the surface of Pt .…”

Manipulating the interaction of Pt NPs with N-hollow carbon spheres by F-doping for boosting oxygen reduction/methanol oxidation reactions

“…In the device, hydrogen, ammonia, and other gas fuels can be selected, but also methanol, ethanol, formic acid, and other liquid fuels. [3][4][5][6] At present, there are great difficulties in the transportation and storage of natural gas. Therefore, liquid fuels based on small organic molecules have great potential for industrial applications.…”