In a major development, Scientists have demonstrated that spent catalysts from the energy industry, as well as the raw material for recycling operations that deliver fresh catalysts and valuable metals, can function as an efficient bifunctional oxygen electrocatalyst and can catalyse the core reactions that facilitate the operation of metal-air batteries.
It can assist in the development of innovative ways for effectively utilizing industrial waste for energy storage in batteries, opening the way to realize the dream of achieving today’s wastage is tomorrow’s energy.
About Hydrogen energy
Hydrogen energy, with its high energy density and clean output, is a promising power generation method for the industry and transportation sectors.
How to produce hydrogen by catalytic decomposition
One of the methods to produce hydrogen is by catalytic decomposition of methane that uses nickel catalyst embedded on alumina or zeolite. After numerous runs, the catalysts get spent owing to carbon choking and lose their activity.
Wasted catalysts are treated in energy-intensive operations such as high-temperature combustion for recycling, which releases a significant amount of COx into the atmosphere, or chemical treatment for metal constituent reclamation. These protocols are neither commercially viable nor environmentally sustainable, thus demanding the development of new methods for effectively utilizing the spent catalyst.
Converting waste to wealth
One of the most suitable routes is to use the retrieved spent catalyst for energy generation and storage applications. The composition of the given spent catalyst, Carbon nanotubes with Ni nanoparticles and porous alumina, are appropriate for direct use as electrocatalyst in electrochemical energy applications, opening up a viable strategy for converting waste to wealth. It can catalyze both electrochemical oxygen evolution (OER) and oxygen reduction reactions (ORR), the core reactions that facilitate the operation of metal-air batteries. This research was recently published in the journal ‘Sustainable Energy Fuels’.
Dr C. Sathiskumar, Dr H.S.S. Ramakrishna Matte and Dr. Neena S. John from the Centre for Nano and Soft Matter Sciences (CeNS), an autonomous institute under the Department of Science & Technology (DST), in collaboration with Hindustan Petroleum Corporation Ltd (HPCL) R&D Green Centre, Bengaluru, have demonstrated that these spent catalysts worked as an efficient bifunctional oxygen electrocatalyst.
For 20 hours and 8 hours, respectively, the spent catalyst shows consistent current density towards OER and ORR. The potential difference for total oxygen electrocatalyst (ΔE) demonstrates that the spent catalyst has a higher bifunctional activity. Furthermore, the spent catalyst used in Zn-air batteries demonstrated excellent charge-discharge performance with great reversibility for up to 45 hours.
This work is supported by the Centre for High Technology (CHT)-Oil and Industry Development Board (OIDB), Hydrogen Corpus Fund that helped in efficient utilization of industrial waste for energy storage applications resulting in the production of green energy in a sustainable manner.
Earlier, the CSIR-CMERI developed a Municipal Solid Waste Processing Facility that helped in achieving the decentralized decimation of solid wastes and also helped in creating value-added end-products from abundantly available redundant material such as dry leaves and dry grass, etc.
About waste to wealth mission project
The waste to wealth mission project was approved under the Prime Minister’s Science Technology and Innovation Advisory Council (PM-STIAC), which is an overarching body for assessment, creation, and implementation of major scientific, technology, and innovation interventions in the country. The aim of the partnership formed is to provide an effective platform for stakeholders to bring together some integrated approaches for effective recycling and reusing waste.