Frank Michael, Bulut Yusuf, Czympiel Lisa, Weißing Rene, Nahrstedt Vanessa, Wilhelm Michael, Grosch Matthias, Raauf Aida, Verma Anjneya, Fischer Thomas, Mathur Sanjay
Department of Chemistry, Institute of Inorganic Chemistry, University of Cologne, Greinstrasse 6, D-50939 Cologne, Germany.
Nanotechnology. 2021 Aug 23;32(46). doi: 10.1088/1361-6528/ac1a96.
The catalytic conversion of nitrogen to ammonia remains an energy-intensive process, demanding advanced concepts for nitrogen fixation. The major obstacle of nitrogen fixation lies in the intrinsically high bond energy (941 kJ mol) of the N≡N molecule and the absence of a permanent dipole in N. This kinetic barrier is addressed in this study by an efficient piezo-enhanced gold catalysis as demonstrated by the room temperature reduction of dinitrogen into ammonia. Au nanostructures were immobilized on thin film piezoelectric support of potassium sodium niobate (KNaNbO, KNN) by chemical vapor deposition of a new Au(III) precursor [MeAu(PyTFP)(HO)](PyTFP = ()-3,3,3-trifluoro-1-(pyridin-2-yl)-prop-1-en-2-olate) that exhibited high volatility (60 °C, 10mbar) and clean decomposition mechanism to produce well adherent elemental gold films on KNN and Ti substrates. The gold-functionalized KNN films served as an efficient catalytic system for ammonia production with a Faradaic efficiency of 18.9% achieved upon ultrasonic actuation. Our results show that the spontaneous polarization of piezoelectric materials under external electrical fields augments the sluggish electron transfer kinetics by creating instant dipoles in adsorbed Nmolecules to deliver a piezo-enhanced catalytic system promising for sustained activation of dinitrogen molecules.
