Smart ideas: Nano-catalytic surfaces

Overview

Green hydrogen (hauwai kākāriki) has the potential to play a key role as a fuel of the future, assisting in Aotearoa New Zealand’s move to renewable energy and reducing dependence on fossil fuel. This innovative project by GNS Science includes new research which will greatly increase the commercial viability of hydrogen as an energy carrier by unlocking alternative, long-life catalysts made from more plentiful materials, using cost-effective techniques.

This programme aims to

• reduce/eliminate the use of rare and costly precious metals such as platinum
• greatly increase the commercial viability of hydrogen as an energy carrier
• reduce barriers in the adoption of hydrogen
• create new manufacturing techniques and export opportunities for New Zealand
• support New Zealand’s goal to be Carbon Zero by 2050

To achieve these aims, we will

• identify and explore earth-abundant transition metal carbides as a promising replacement electrocatalyst for platinum
• develop novel manufacturing methods to apply these catalysts for hauwai kākāriki production and the reliable operation of fuel cells

The project

Hydrogen can play a key role in Carbon Zero goals

A hydrogen fuel-based economy creates minimal greenhouse gas emissions, provides security of fuel supply, and is gentle on the environment. Yet heavy reliance on fossil fuels to produce hydrogen and the high manufacturing cost of fuel cells both hinder this much-needed transition. The eco-friendly production of hydrogen also requires platinum catalysts, which are scarce and expensive.

GNS Science’s Prasanth Gupta and John Kennedy are leading ground-breaking research that aims to overcome these challenges and greatly increase the commercial viability of hydrogen as an energy carrier, by moving away from precious metals and unlocking more plentiful and cost-effective alternatives.

Mimicking platinum: Novel catalyst designs for water-splitting and fuel cells

The excellent catalytic properties of platinum group metals stems from their optimal valence electron configuration (the way the electrons behave at the edge of the atom). Our work aims to combine relatively abundant transition metals, like tungsten or molybdenum, with carbon atoms to form transition metal compounds – metallic carbides – that have similar electron distribution as platinum group metals in order to mimic its catalytic properties.

However, for these catalysts to perform as well as traditional platinum, they need to be applied as ultra-fine nanoparticles (< 5 nm) to maximise their active surface area. Until now, it has been difficult to synthesise such metal carbides as nanoparticles (< 5 nm particles). This is because the conventional approach to synthesising metal carbides requires exposure to very high temperatures. This tends to cause uncontrollable agglomeration – the particles melt together – leading to large particle sizes (>> 5 nm) and a poor available surface area for catalysis.

In this research we propose an innovative synthesis route based on ion beam engineering to make transition metal carbide nano-catalytic surfaces with low particle sizes and therefore high surface areas. We hope this means we can make a cost-effective catalytic surface with high durability and great performance. Our team brings expertise in the fields of materials physics and engineering, catalyst chemistry and nanomanufacturing. If our research is successful, eco-friendly hydrogen production and highly efficient, long-lasting fuel cells become economically viable, supporting Aotearoa New Zealand’s vision of a low-carbon economy.