Safe space: improving the "clean" methanol fuel cells using a protective carbon shell

December 04, 2020

Because of the many environmental problems caused by the use of fossil fuels, many scientists worldwide are focused on finding efficient alternatives. Though high hopes have been placed on hydrogen fuel cells, the reality is that transporting, storing, and using pure hydrogen comes with a huge added cost, making this process challenging with current technology. In contrast, methanol (CH3O3), a type of alcohol, does not require cold storage, has a higher energy density, and is easier and safer to transport. Thus, a transition into a methanol-based economy is a more realistic goal.

However, producing electricity from methanol at room temperature requires a direct methanol fuel cell (DMFC); a device that, so far, offers subpar performance. One of the main problems in DMFCs is the undesired "methanol oxidation" reaction, which occurs during methanol crossover," that is, when it passes from the anode to the cathode. This reaction results in the degradation of the platinum (Pt) catalyst that is essential for the cell's operation. Although certain strategies to mitigate this problem have been proposed, so far none has been good enough owing to cost or stability issues.

Fortunately, in a recent study published in ACS Applied Materials & Interfaces, a team of scientists from Korea has come up with a creative and effective solution. They fabricated--through a relatively simple procedure--a catalyst made of Pt nanoparticles encapsulated within a carbon shell. This shell forms an almost impenetrable carbon network with small openings caused by nitrogen defects. While oxygen, one of the main reactants in DMFCs, can reach the Pt catalyst through these "holes," methanol molecules are too big to pass through. "The carbon shell acts as a molecular sieve and provides selectivity toward the desired reactants, which can actually reach the catalyst sites. This prevents the undesirable reaction of the Pt cores," explains Professor Oh Joong Kwon from Incheon National University, Korea, who led the study.

The scientists conducted various types of experiments to characterize the overall structure and composition of the prepared catalyst and proved that oxygen could make it through the carbon shell and methanol could not. They also found a straightforward way to tune the number of defects in the shell by simply changing the temperature during a heat treatment step. In subsequent experimental comparisons, their novel shelled catalyst outperformed commercial Pt catalysts and also offered much higher stability.

Prof Kwon has been working on improving fuel cell catalysts for the past 10 years, motivated by the many ways in which this technology could find its way into our daily lives. "DMFCs have a higher energy density than lithium-ion batteries and could therefore become alternative power sources for portable devices, such as laptops and smartphones," he remarks.

With the future of our planet on the line, switching to alternative fuels should be one of humanity's top goals, and this study is a remarkable step in the right direction.

Authors: Dohyeon Lee (1), Sujin Gok (1), Youngkwang Kim (2), Yung-Eun Sung (2), Eunjik Lee (3), Ji-Hoon Jang (3), Jee Youn Hwang (3), Oh Joong Kwon (1) and Taeho Lim (4)

Title of original paper: Methanol Tolerant Pt?C Core?Shell Cathode Catalyst for Direct Methanol Fuel Cells

Journal:ACS Applied Materials & Interfaces

DOI: 10.1021/acsami.0c07812

(1) Department of Energy and Chemical Engineering, Incheon National University
(2) School of Chemical and Biological Engineering, Seoul National University
(3) Research & Development Division, Hyundai Motor Group
(4) Department of Chemical Engineering, Soongsil University

About Incheon National University

Incheon National University (INU) is a comprehensive, student-focused university. It was founded in 1979 and given university status in 1988. One of the largest universities in South Korea, it houses nearly 14,000 students and 500 faculty members. In 2010, INU merged with Incheon City College to expand capacity and open more curricula. With its commitment to academic excellence and an unrelenting devotion to innovative research, INU offers its students real-world internship experiences. INU not only focuses on studying and learning but also strives to provide a supportive environment for students to follow their passion, grow, and, as their slogan says, be INspired. Website:

About the author

Professor Oh Joong Kwon received his PhD from the School of Chemical and Biological Engineering, Seoul National University in 2007 and a postdoctoral fellowship at the Research Center for Energy and Conversion Storage, Seoul National University. He was appointed as a full-time lecturer at the Department of Mechanical Engineering at Incheon National University in 2008. Then, he switched to the Department of Energy and Chemical Engineering at Incheon National University and was promoted to full professor in 2019. He has been continuously engaged in studies of fuel cell catalysts and electrochemical deposition as director of several research funds supported by the government and companies.


Incheon National University

Related Fossil Fuels Articles from Brightsurf:

How green hydrogen can become cheap enough to compete with fossil fuels
The green hydrogen revolution is coming, and Australia is perfectly placed to take advantage of it, an analysis of production costs by UNSW engineers has shown.

A key to cheaper renewable fuels: keeping iron from rusting
Washington State University researchers have made a key first step in economically converting plant materials to fuels: keeping iron from rusting.

New catalyst efficiently turns carbon dioxide into useful fuels and chemicals
By efficiently converting CO2 into complex hydrocarbon products, a new catalyst developed by a team of Brown researchers could potentially aid in large-scale efforts to recycle excess carbon dioxide.

Agriculture replaces fossil fuels as largest human source of sulfur to the environment
Historically, coal-fired power plants were the largest source of reactive sulfur, a component of acid rain, to the biosphere.

Agriculture replaces fossil fuels as largest human source of sulfur in the environment
New research identifies fertilizer and pesticide applications to croplands as the largest source of sulfur in the environment -- up to 10 times higher than the peak sulfur load seen in the second half of the 20th century, during the days of acid rain.

The secret to renewable solar fuels is an off-and-on again relationship
Copper that was once bound with oxygen is better at converting CO2 into renewable fuels than copper that was never bound to oxygen, according to Berkeley Lab and Caltech scientists.

'Blinking" crystals may convert CO2 into fuels
Imagine tiny crystals that ''blink'' like fireflies and can convert carbon dioxide, a key cause of climate change, into fuels.

Biomass fuels can significantly mitigate global warming
'Every crop we tested had a very significant mitigation capacity despite being grown on very different soils and under natural climate variability,' says Dr.

Plastics, fuels and chemical feedstocks from CO2? They're working on it
Four SUNCAT scientists describe recent research results related to the quest to capture CO2 from the smokestacks of factories and power plants and use renewable energy to turn it into industrial feedstocks and fuels.

Fossil fuels increasingly offer a poor return on energy investment
University of Leeds researchers have calculated the EROI for fossil fuels over a 16 year period and found that at the finished fuel stage, the ratios are much closer to those of renewable energy sources -- roughly 6:1, and potentially as low as 3:1 in the case of electricity.

Read More: Fossil Fuels News and Fossil Fuels Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to