Advent Technologies Holdings Inc (<a href="https://www.nasdaq.com/market-activity/stocks/adn/real-time" target="_blank">NASDAQ:ADN</a>), a Boston, Massachusetts-based company focused on fuel cell and hydrogen technologies, will partner with Germany’s Siemens Energy AG (<a href="https://www.boerse-frankfurt.de/equity/siemens-energy-ag" target="_blank">ETR:ENR</a>) to develop a fuel cell for maritime applications.