(418f) Synergistic Effects between Geometric and Electronic Factors on Crystallized Polymer-Coated Pt Catalyst for Hydrogen Evolution Reaction

One way to deal with the growing energy demands and the vulnerability to sustainable energy is to discover the energy resources that are environmentally friendly, renewable, and plentiful.[1] Among several materials with the above characteristics, hydrogen has been considered a key fuel in the design of innovative energy generation and storage technologies.[2-3] One very widely adopted way to produce hydrogen is a half-reaction of electrochemical water splitting called hydrogen evolution reaction (HER) which requires an appropriate catalyst to enhance the reaction efficiency.[4-5] In this reaction, platinum (Pt) has been widely used due to its ideal d-orbital tendency leading to a low overpotential value.

However, although Pt-based materials have an excellent electronic feature with a metallic nature, there has been a need for improvement of the desorption rate (Tafel reaction) of hydrogen gas compared to adsorption rate (Volmer reaction) of hydrogen. For the above-mentioned reason, we newly designed diverse crystallized polymer-coated Pt catalysts to significantly enhance the Tafel reaction for hydrogen gas desorption, and suggested a candidate material that surpasses the conventional Pt. Further, to obtain theoretical insights into the catalytic activity priority of the designed structures, we systematically analyzed the correlations between hydrogen binding strength (∆G_H*) and electronic/geometric properties such as electron charge state, p-/d-orbital variation, electrostatic interaction, and strain effect. These theoretical investigations were able to clearly describe the origin of enhanced HER performance by boosting Tafel reaction. In addition, our results are consistent with the experimental activities of the newly designed structures and their activity order from thermodynamic and kinetic viewpoints.

References

[1] W. Lubitz and W. Tumas, Chem Rev, (107), 2007, pp. 3900-3903.

[2] N. L. Panwar, S. C. Kaushik and S. Kothari, Renew Sust Energ Rev, (15), 2011, pp. 1513-1524.

[3] Z. G. Yang, J. L. Zhang, M. C. W. Kintner-Meyer, X. C. Lu, D. W. Choi, J. P. Lemmon and J. Liu, Chem Rev, (111), 2011, pp. 3577-3613.

[4] M. S. Dresselhaus and I. L. Thomas, Nature, (414), 2001, pp. 332-337.

[5] Y. Jiao, Y. Zheng, M. T. Jaroniec and S. Z. Qiao, Chem Soc Rev, (44), 2015, pp. 2060-2086