Activity and stability of cobalt phosphides for hydrogen evolution upon water splitting
Late transition metal phosphides have been reported to have high activity for catalyzing hydrogen evolution reaction (HER), yet their active site and stability are not well-understood. Here we report systematic activity and stability study of CoP for HER by combining electrochemical measurements for...
| Main Authors: | , , , , , , |
|---|---|
| Other Authors: | |
| Format: | Article |
| Language: | en_US |
| Published: |
Elsevier
2018
|
| Online Access: | http://hdl.handle.net/1721.1/118893 https://orcid.org/0000-0001-5703-3266 https://orcid.org/0000-0002-2919-3235 https://orcid.org/0000-0003-2820-7006 https://orcid.org/0000-0002-6879-9424 https://orcid.org/0000-0001-6755-8760 https://orcid.org/0000-0002-4593-2966 |
| _version_ | 1826205921483685888 |
|---|---|
| author | Ha, Don-Hyung Han, Binghong Risch, Marcel Giordano, Livia Yao, Koffi Pierre Claver Karayaylali, Pinar Shao-Horn, Yang |
| author2 | Massachusetts Institute of Technology. Department of Materials Science and Engineering |
| author_facet | Massachusetts Institute of Technology. Department of Materials Science and Engineering Ha, Don-Hyung Han, Binghong Risch, Marcel Giordano, Livia Yao, Koffi Pierre Claver Karayaylali, Pinar Shao-Horn, Yang |
| author_sort | Ha, Don-Hyung |
| collection | MIT |
| description | Late transition metal phosphides have been reported to have high activity for catalyzing hydrogen evolution reaction (HER), yet their active site and stability are not well-understood. Here we report systematic activity and stability study of CoP for HER by combining electrochemical measurements for CoP nanoparticles (NPs) with ex situ and in situ synchrotron X-ray absorption (XAS) spectroscopy at phosphorus and cobalt K edges, as well as density functional theory (DFT) calculations. Colloidally synthesized CoP NPs showed high HER activity in both acid and base electrolytes, comparable to previous work, where no significant pH dependence was observed. Transmission electron microscopy-energy dispersive spectroscopy study of CoP NPs before and after exposure to potentials in the range from 0 to 1.4 V vs. the reversible hydrogen electrode (RHE) revealed that the P/Co ratio reduced with increasing potential in the potentiostatic measurements prior to HER measurements. The reduced P/Co ratio was accompanied with the emergence of (oxy)phosphate(s) as revealed by XAS, and reduced specific HER activity, suggesting the important role of P in catalyzing HER. This hypothesis was further supported by DFT calculations of HER on the most stable (011) surface of CoP and voltage dependent intensities of both phosphide and phosphate components from P-K edge X-ray spectroscopy. This work highlights the need of stabilizing metal phosphides and optimizing their surface P sites in order to realize the practical use of metal phosphides to catalyze HER in electrochemical and photoelectrochemical devices. Keywords: Metal phosphide; Hydrogen evolution reaction; HER; Catalysis; Water splitting; Electrocatalysis |
| first_indexed | 2024-09-23T13:21:10Z |
| format | Article |
| id | mit-1721.1/118893 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T13:21:10Z |
| publishDate | 2018 |
| publisher | Elsevier |
| record_format | dspace |
| spelling | mit-1721.1/1188932022-09-28T13:37:23Z Activity and stability of cobalt phosphides for hydrogen evolution upon water splitting Ha, Don-Hyung Han, Binghong Risch, Marcel Giordano, Livia Yao, Koffi Pierre Claver Karayaylali, Pinar Shao-Horn, Yang Massachusetts Institute of Technology. Department of Materials Science and Engineering Massachusetts Institute of Technology. Department of Mechanical Engineering Massachusetts Institute of Technology. Research Laboratory of Electronics Shao-Horn, Yang Ha, Don-Hyung Han, Binghong Risch, Marcel Giordano, Livia Yao, Koffi Pierre Claver Karayaylali, Pinar Shao-Horn, Yang Late transition metal phosphides have been reported to have high activity for catalyzing hydrogen evolution reaction (HER), yet their active site and stability are not well-understood. Here we report systematic activity and stability study of CoP for HER by combining electrochemical measurements for CoP nanoparticles (NPs) with ex situ and in situ synchrotron X-ray absorption (XAS) spectroscopy at phosphorus and cobalt K edges, as well as density functional theory (DFT) calculations. Colloidally synthesized CoP NPs showed high HER activity in both acid and base electrolytes, comparable to previous work, where no significant pH dependence was observed. Transmission electron microscopy-energy dispersive spectroscopy study of CoP NPs before and after exposure to potentials in the range from 0 to 1.4 V vs. the reversible hydrogen electrode (RHE) revealed that the P/Co ratio reduced with increasing potential in the potentiostatic measurements prior to HER measurements. The reduced P/Co ratio was accompanied with the emergence of (oxy)phosphate(s) as revealed by XAS, and reduced specific HER activity, suggesting the important role of P in catalyzing HER. This hypothesis was further supported by DFT calculations of HER on the most stable (011) surface of CoP and voltage dependent intensities of both phosphide and phosphate components from P-K edge X-ray spectroscopy. This work highlights the need of stabilizing metal phosphides and optimizing their surface P sites in order to realize the practical use of metal phosphides to catalyze HER in electrochemical and photoelectrochemical devices. Keywords: Metal phosphide; Hydrogen evolution reaction; HER; Catalysis; Water splitting; Electrocatalysis 2018-11-05T19:53:37Z 2018-11-05T19:53:37Z 2016-04 2016-04 Article http://purl.org/eprint/type/JournalArticle 2211-2855 http://hdl.handle.net/1721.1/118893 Ha, Don-Hyung et al. “Activity and Stability of Cobalt Phosphides for Hydrogen Evolution Upon Water Splitting.” Nano Energy 29 (November 2016): 37–45 © 2016 Elsevier Ltd https://orcid.org/0000-0001-5703-3266 https://orcid.org/0000-0002-2919-3235 https://orcid.org/0000-0003-2820-7006 https://orcid.org/0000-0002-6879-9424 https://orcid.org/0000-0001-6755-8760 https://orcid.org/0000-0002-4593-2966 en_US http://dx.doi.org/10.1016/j.nanoen.2016.04.034 Nano Energy Creative Commons Attribution-NonCommercial-NoDerivs License http://creativecommons.org/licenses/by-nc-nd/4.0/ application/pdf Elsevier Prof. Shao-Horn via Angie Locknar |
| spellingShingle | Ha, Don-Hyung Han, Binghong Risch, Marcel Giordano, Livia Yao, Koffi Pierre Claver Karayaylali, Pinar Shao-Horn, Yang Activity and stability of cobalt phosphides for hydrogen evolution upon water splitting |
| title | Activity and stability of cobalt phosphides for hydrogen evolution upon water splitting |
| title_full | Activity and stability of cobalt phosphides for hydrogen evolution upon water splitting |
| title_fullStr | Activity and stability of cobalt phosphides for hydrogen evolution upon water splitting |
| title_full_unstemmed | Activity and stability of cobalt phosphides for hydrogen evolution upon water splitting |
| title_short | Activity and stability of cobalt phosphides for hydrogen evolution upon water splitting |
| title_sort | activity and stability of cobalt phosphides for hydrogen evolution upon water splitting |
| url | http://hdl.handle.net/1721.1/118893 https://orcid.org/0000-0001-5703-3266 https://orcid.org/0000-0002-2919-3235 https://orcid.org/0000-0003-2820-7006 https://orcid.org/0000-0002-6879-9424 https://orcid.org/0000-0001-6755-8760 https://orcid.org/0000-0002-4593-2966 |
| work_keys_str_mv | AT hadonhyung activityandstabilityofcobaltphosphidesforhydrogenevolutionuponwatersplitting AT hanbinghong activityandstabilityofcobaltphosphidesforhydrogenevolutionuponwatersplitting AT rischmarcel activityandstabilityofcobaltphosphidesforhydrogenevolutionuponwatersplitting AT giordanolivia activityandstabilityofcobaltphosphidesforhydrogenevolutionuponwatersplitting AT yaokoffipierreclaver activityandstabilityofcobaltphosphidesforhydrogenevolutionuponwatersplitting AT karayaylalipinar activityandstabilityofcobaltphosphidesforhydrogenevolutionuponwatersplitting AT shaohornyang activityandstabilityofcobaltphosphidesforhydrogenevolutionuponwatersplitting |