Technical University of Denmark

Realisation of electrochemical nitrogen reduction to ammonia has proven to be a herculean scientific challenge. Recently, a focus on Lithium-mediated synthesis has delivered promising results. Last year a team from Monash University in Australia unveiled their phosphonium “proton shuttle” method, and this year have reported nearly 100% Faradaic efficiency for the reaction (with promising reaction rates). Late last year, a team from the Technical University of Demark (DTU) reported that addition of small amounts of oxygen gas drastically increased Faradaic efficiencies and production rates. The results push electrochemical synthesis R&D ever-closer to elusive benchmarks set for commercial realisation.

NEWS BRIEF: A paper published this week in Nature addresses the challenge of accurately reporting synthesis rates for electrochemical ammonia production technologies. According to the authors, from Stanford University, the Technical University of Denmark (DTU), and Imperial College London, it is not always clear if new technologies really synthesize ammonia, or if the researchers simply measured contaminants. This is because, at experimental scale, materially significant amounts of ammonia (or other nitrogen-containing molecules) could be present in the air, membranes, catalysts, or simply the researchers' breath. To support the development of viable electrochemical ammonia synthesis technologies, the authors propose "benchmarking protocols," and "a standardized set of control experiments."

In the last 12 months ... The research community has made great progress toward solving the "selectivity challenge" in electrochemical ammonia synthesis. Although, rather than an actual solution, mostly what we have is a range of sophisticated work-arounds that succeed in making this problem moot.

New research coming out of Stanford University suggests a fascinating new direction for electrochemical ammonia synthesis technology development. The US-Danish team of scientists at SUNCAT, tasked with finding new catalysts for electrochemical ammonia production, saw that 'selectivity' posed a tremendous challenge - in other words, most of the energy used by renewable ammonia production systems went into making hydrogen instead of making ammonia. The new SUNCAT solution does not overcome this selectivity challenge. It doesn't even try. Instead, these researchers have avoided the problem completely.