Researchers in Australia develop low-cost water-splitting catalyst that offers comparable performance to platinum
16 December 2019
A team of researchers in Australia has developed a Janus nanoparticle catalyst with a nickel–iron oxide interface and multi-site functionality for a highly efficient hydrogen evolution reaction with a comparable performance to the benchmark platinum on carbon catalyst. (Janus particles feature surfaces with two or more distinct properties.) An open-access paper on their work is published in the journal Nature Communications.
Schematic representation of the Ni and Fe nanoparticles and the Ni-Fe Janus nanoparticles synthesis through the oleate-assisted micelle formation and the illustration on the HER across the Ni-γ-Fe2O3 interface in alkaline medium. Suryanto et al.
Iron and nickel, which are found in abundance on Earth, would replace precious metals ruthenium, platinum and iridium that up until now are regarded as benchmark catalysts in the water-splitting process.
Density functional theory calculations reveal that the hydrogen evolution reaction catalytic activity of the nanoparticle is induced by the strong electronic coupling effect between the iron oxide and the nickel at the interface.
Remarkably, the catalyst also exhibits extraordinary oxygen evolution reaction activity, enabling an active and stable bi-functional catalyst for whole cell water-splitting with, to the best of our knowledge, the highest energy efficiency (83.7%) reported to date.
—Suryanto et al.
In 2015, UNSW School of Chemistry’s Professor Chuan Zhao’s team invented a nickel-iron electrode for oxygen generation with a record-high efficiency. However, Prof Zhao says that on their own, iron and nickel are not good catalysts for hydrogen generation, but where they join at the nanoscale is “where the magic happens”.
The nanoscale interface fundamentally changes the property of these materials. Our results show the nickel-iron catalyst can be as active as the platinum one for hydrogen generation.
An additional benefit is that our nickel-iron electrode can catalyse both the hydrogen and oxygen generation, so not only could we slash the production costs by using Earth-abundant elements, but also the costs of manufacturing one catalyst instead of two.
—Prof Zhao
Iron and nickel are currently priced at $0.13 and $19.65 a kilogram. By contrast, ruthenium, platinum and iridium are priced at $11.77, $42.13 and $69.58 per gram—in other words, thousands of times more expensive.
… this work demonstrates that the introduction of asymmetry in an electrocatalyst structure could induce unprecedented synergistic effect for electrocatalysis. Through this approach, we have overcome the practical limitation of Ni–Fe mixed oxides for overall water electrolysis due to the poor HER activity. Additionally, having similar active sites for both OER and HER results in the preservation of catalyst structure and activity against electrode corrosion induced by power interruptions, which is ideal for a water electrolyzer powered by intermittent renewable energy sources.
Beyond, it is also our hope that this multi-site functionality catalyst design can help to expedite the conception-to-commercialization process of other multi-metallic nanoparticle electrocatalysts with different compositions and structures that exhibit distinct interfaces for various electrolytic applications such as CO2 reduction reactions and nitrogen reduction reactions.
—Suryanto et al.
Resources
Bryan H. R. Suryanto et al. (2019) “Overall electrochemical splitting of water at the heterogeneous interface of nickel and iron oxide,” Nature Communications doi: 10.1038/s41467-019-13415-8
From the linked paper:
'Based on the calculated HER and OER Faradaic efficiency of approximately ~100% at j = 10 mA cm−2 (Supplementary Fig. 31), the energy efficiency of the Ni–Fe NP cell is calculated to be 83.7% with iR-correction (79.4% without iR- correction).'
They also claim excellent stability.
Potentially this would appear able to solve generation of hydrogen from renewables, and hence overcome storage issues, which straight electricity production falls down on.
Posted by: Davemart | 16 December 2019 at 07:14 AM
Converting electricity to hydrogen leaves you with the problem of storing the hydrogen. Compression is lossy and requires expensive tanks. Liquefaction is even lossier. Conversion to liquids like ammonia incurs energy penalties in both directions.
As Steven Chu said 10 years ago, hydrogen requires 4 miracles: production, distribution, storage and fuel cells. Even if production and FCs are now "solved", distribution and storage are still not doing at all well, nothing compared to what we need to replace fossil fuels.
OTOH, if hydrogen only needed to be a niche player instead of the heavy lifter, we would probably be able to make things work with what we've already got.
Posted by: Engineer-Poet | 16 December 2019 at 09:33 AM
As fossil fuels become less abundant and alternatives more,
we reach a balance over time. The all or nothing idea misses the point.
Posted by: SJC | 16 December 2019 at 11:10 AM
Storage is possible in depleted natural gas fields, in salt caverns, and in the NG pipeline newtwok in vast quantities, none of which require a lot of compression.
Hydrides etc are also being developed.
I would provide links, but it is apparent that some have been ignoring them for years, as they do not fit their preconceptions..
Posted by: Davemart | 17 December 2019 at 10:09 AM
It is good we are thinking beyond petroleum to the days when it is scarce.
Posted by: SJC | 17 December 2019 at 10:40 PM
I've seen plenty of talk-talk about using old oil and NG wells for H2 storage. So far I have not seen it done in practice. Along the US Gulf coast there is storage, but it appears to be in solution-mined cavities in salt domes rather than the more common porous stones. This eliminates any difficulties with bacteria metabolizing hydrogen and sulfates to hydrogen sulfide.
Even if you can find the volume, finding the money and energy to fill it isn't going to be easy:
Using hydrogen is perhaps THE most difficult and expensive way to replace fossil fuels. In other words, if there was a conspiracy to slow or prevent the replacement of fossil fuels, hydrogen is what they would push to the exclusion of all else... and you know damn well there is such a conspiracy.
Posted by: Engineer-Poet | 18 December 2019 at 06:52 AM
It is a poor method of argument to refuse to focus on the obvious benefits of cheap hydrogen and instead present 'and another thing' argumentation about completely different aspects of the technology.
Posted by: Davemart | 19 December 2019 at 01:53 AM
For hydrogen storage vast amounts, and I mean volumes of the right orger of magnitude to assist seasonal storage, although perhaps not completely cover it without addition, can be done just in the existing naturas gas pipeline network.
Here is Germany, with their plans for storage of power to gas:
https://www.gtai.de/gtai-en/invest/industries/life-sciences/germany-s-gas-network-infrastructure-the-advantage-104638
Since we are not currently producing large amounts of hydrogen from renewables to require storage, it is wholly unreasonable to expect that the facilities for mass storage should be up and running.
But here are UK studies of storage in depleted natural gas fields:
http://www.h2fcsupergen.com/news/a-feasibility-study-of-storing-hydrogen-in-depleted-gas-reservoirs/
And a more recent one:
https://www.researchgate.net/publication/297721804_Seasonal_storage_of_hydrogen_in_a_depleted_natural_gas_reservoir
I downloaded the full paper, and those who are interested can do the same thing
The bottom line is that we already have vast experience in NG storage underground, and although hydrogen has somewhat different although analogous characteristics no one has found any showstoppers.
And really cheap hydrogen from renewables is not going to help at all, but will be stopped dead by assumed insuperanble problems in storage?
That simply does not make any sense.
Posted by: Davemart | 19 December 2019 at 02:03 AM
The ONLY bulk cheap hydrogen comes from fossil fuels. That's why the fossil fuel interests want "alternatives" focused on it to the exclusion of all else.
Posted by: Engineer-Poet | 19 December 2019 at 02:40 AM
Here is the 2018 DOE progress report on hydrogen:
https://www.nrel.gov/docs/fy19osti/73353.pdf
Renewables are getting cheaper and cheaper.
The issue is that they are intermittent, so need buffering and storage.
Hydrogen can provide both, with the transition to and from hydrogen being the issue.
Perfectly conventional electrolysis is approaching the cost effectiveness to make that a viable option, even when the electrolyser to take advantage of renewables only when they are in surplus is perfectly conventional, with other options such as high temperature electrolysis or using the assistance of th heat presently vented from industrial processes doing even better.
The option above, or one of a number of alternatives, would shift the costs into fully competitive ones with fossil fuels.
Those are the numbers.
Posted by: Davemart | 19 December 2019 at 12:27 PM
The 2020 target is 43 kWh/kg and $2.30/kg levelized cost of production (Table 1, p. 43). This means that the cost of energy cannot exceed $0.0534/kWh even if the capital and O&M cost of the H2 system is zero.
Do I have to point out just how INSANE this is?
Posted by: Engineer-Poet | 23 December 2019 at 05:13 PM