02223nas a2200241   4500008004100000022001400041245009300055210006900148260000800217300001400225490000700239520137500246653001501621653001601636653002101652653003201673653004501705653003101750100002401781700002901805700002601834856012101860       2026                        eng d  a2168-048500aSilico imine-based ligand engineering of CALF-20 for electrocatalytic ammonia production0 aSilico iminebased ligand engineering of CALF20 for electrocataly  cAPR  a7217-72280 v143 a<p>
	Electrocatalytic ammonia synthesis is emerging as a globally compelling, sustainable alternative to the Haber-Bosch process under ambient conditions. As a result, active-site engineering has taken center stage in the development of stable and effective electrocatalysts. In this work, we report how the introduction of an imine group in the ligand backbone of CALF-20, a Zn-based, moisture-stable MOF with high surface area, results in the formation of an N-4 macrocycle for transition-metal anchoring. PBE + D3 calculations, supported by spectroscopic, ab initio molecular dynamics, and electronic analyses, identify Fe-bound modified CALF-20 as the most stable configuration among the Mn-, Fe-, Co-, Ni-, Cu-, Ru-, Rh-, Ag-, and Au-anchored within the modified CALF-20 framework. Upon modification, the d-band center shifts from -5.08 to -4.44 eV in M-Fe-CALF-20. Adsorption studies confirm activation of both N-2 and NO2, reflected by bond elongation and red-shifted IR peaks. Mechanistic studies show that M-Fe-CALF-20 selectively facilitates NH3 formation, exhibiting PDS values of 0.69 and 0.62 eV for the NRR and NO2RR, respectively, while a competitive adsorption shows a clear preference over HER. Our study illustrates how functionalization tunes CALF-20 for dual application as an adsorbent and as an electrocatalyst for NH3 synthesis and storage.</p>
10aAdsorption10aCALF-20 MOF10aelectrocatalysis10ahydrogen evolution reaction10anitrogen oxide reductionreaction (NO2RR)10anitrogen reductionreaction1 aSamudre, Nikhil, S.1 aSamal, Pragnya, Paramita1 aKrishnamurty, Sailaja  uhttps://library.ncl.res.in/content/silico-imine-based-ligand-engineering-calf-20-electrocatalytic-ammonia-production