
Dr Matthew Mayer
After our recent face-to-face meeting in Dublin, Danielle Nicholson at Pintail Limited posed a set of questions to PI Dr Matthew Mayer, Helmholtz-Zentrum Berlin. Dr Mayer is an expert on photoelectrochemical and electrocatalytic water splitting and CO2 reduction, nanomaterials synthesis, and photovoltaics. Enjoy!
How and when did you first become interested in chemistry?
I started my undergraduate studies (in Boise, Idaho, USA) with the goal of becoming a pharmacist. But when I took the course Organic Chemistry, something changed for me. That course makes you draw lots of molecules, thinking about their physical structure and how they move and interact with each other. This triggered in me a new scientific curiosity, and I decided to change my focus to chemistry, with the goal of doing research.
What is it about chemistry that interests you most these days?
I am fascinated by how photons (light) interact with stuff. This includes things like using light to excite electrons to drive chemical reactions, or to stimulate molecular vibrations which reveal details about molecules stuck on a catalyst surface. Lately, we focus on using photons to examine the electron structure of materials and interfaces during electrochemical reactions, by X-ray spectroscopy.
What do you see as the biggest challenge to the photoelectrochemistry field right now?
Urgency! Over the last 3 to 4 decades we in the photoelectrochemistry field have come up with many elegant device concepts and new materials for “artificial photosynthesis”, but identifying an efficient, stable, and scalable approach has remained elusive. Meanwhile, we are rocketing past the planetary boundaries and we need to reinvent our chemicals and fuels industries yesterday to avoid catastrophe.
Please describe your group and facilities.
Our group name at HZB is Electrochemical Conversion, established in 2017 as a Helmholtz Young Investigator Group. We are a very international group (presently 10 members from 9 different countries) based at the Wannsee campus of HZB. There we have labs for materials synthesis (by chemical and physical methods), electrode preparation, and photo- and electro-chemical test stations with analysis of gas and liquid products. We also perform experiments using the BESSY II synchrotron, which is on the other side of the city of Berlin.

Dr Matt Mayer's Group at the HZB boating on the river Spree in summer 2021
Your work seems incredibly varied: supervising PhD students, grant writing and admin, lab work, travel. Which aspect/s do you enjoy most?
I enjoy the variety! But I most enjoy the moments of creativity – such as coming up with new ways to study something, or devising unique solutions to experimental problems, or generating new ideas for proposals. Doing all of these together with creative colleagues is very fulfilling to me personally.
For how long have you been in Berlin at the HZB? What is the best thing about working there?
I joined HZB in the spring of 2017, so it’s been nearly five years since starting our group here. Some of the best things about working here are the scientific infrastructure and expertise. We have so many different instruments and methods available, and experts on their use, which is a key advantage of working at HZB.
Talk us through your group's role in FlowPhotoChem. Are there any unforeseen obstacles to your group's work in the project? If so, please describe how they are being addressed.
We are working on the electrochemical conversion of carbon monoxide to value-added products, developing novel catalysts and designing experiments to study the reaction mechanisms which dictate which products are formed. A challenge we are encountering is that these systems can behave quite differently from carbon dioxide conversion systems (where we have more prior experience). We tackle the challenge by working with the project’s consortium to systematically understand and optimize many different aspects of the devices together.
What do you find most exciting about the FlowPhotoChem project?
The fact that we have regular discussions with experts from quite different fields is something very unique and exciting about this collaborative project since it stimulates us to think holistically about the entire system we are pursuing, rather than just the specific aspects of our day-to-day work.
Had you worked with Pau or any of the partners prior to FlowPhotoChem? If so, who and where?
When I was a postdoc at EPFL, I was part of the FP7-JTI project PECDEMO, where we collaborated with the FlowPhotoChem colleagues from DLR (M. Wullenkord) on photoelectrochemical water splitting devices. I also worked with Sophia Haussener’s group on photoanode materials at that time.
What do you like to do in your free time?
Bicycle riding around Berlin, playing instruments (amateur at guitar, bass & drums), and heading to the mountains for hiking, biking & climbing.