Toward Sabatier Optimal for Ammonia Synthesis with Paramagnetic Phase of Ferromagnetic Transition Metal Catalysts

Abstract

The Sabatier principle defines the essential criteria for being an ideal catalyst in heterogeneous catalysis, while approaching the Sabatier optimal is a major pursuit in catalyst design. The Haber–Bosch (H-B) process, converting nitrogen (N2) and hydrogen (H2) to ammonia (NH3), is a holy grail reaction for humans and also a great model reaction for fundamental research, where the established volcano plot between ammonia synthesis activity and nitrogen binding energy among metals has successfully guided new catalyst design. However, reaching the top of the activity volcano is still very challenging. Herein, we identify an elegant strategy to promote the ferromagnetic (FM) catalysts to be the Sabatier optimal of ammonia synthesis via a second-order ferromagnetic–paramagnetic phase transition, which represents an ideal and novel interdisciplinary of the aforementioned century-old classic principle, reaction, and theory in chemistry, physics, and material science. The paramagnetic (PM) Co and Ni metals could have 2–4 orders of magnitude higher ammonia synthesis activity than their ferromagnetic counterparts, holding the potential to achieve a near-ambient H-B process. We believe that our discovery will open a novel avenue for revisiting the catalytic performances of paramagnetic phases of ferromagnetic materials in heterogeneous catalysis.

Selective NOx– Electroreduction to Ammonia on Isolated Ru Sites

“…Inspired by the Sabatier principle, where Ru locates at the top of the volcano plot for the Haber–Bosch NH 3 synthesis volcano, we demonstrate that atomically dispersed Ru sites loaded on nitrogenated carbon (Ru SA-NC) exhibited impressive activity and NH 3 selectivity for both nitrate and nitrite reduction in basic conditions. The Ru SA-NC catalyst delivered maximal Faradaic efficiencies of 97.8% (NO 2 – reduction) and 72.8% (NO 3 – reduction) toward NH 3 at −0.6 and −0.4 V vs RHE, respectively, which were significantly higher than that of Ru nanoparticles.…”

Field‐assisted electrocatalysts spark sulfur redox kinetics: From fundamentals to applications

“…How to distinguish the detailed mechanisms of electrocatalytic process for different magnetic properties, especially for their quantum spin-exchange interaction, is strategic yet remains an uncultivated land. [105][106][107][108]…”

A High-Throughput Screening toward Efficient Nitrogen Fixation: Transition Metal Single-Atom Catalysts Anchored on an Emerging π–π Conjugated Graphitic Carbon Nitride (g-C10N3) Substrate with Dirac Dispersion

“…It is generally recognized that the coexistent occupied and empty d orbitals can back-donate π-electrons to and accept lone-pair electrons from N 2 , which determines the origin of the NRR activity for these transition metal (TM) containing catalysts. 34 Despite this, issues still exist. Two main causes hinder the design of highly efficient N 2 -to-NH 3 catalysts: the low activity toward the activation of inert N 2 as a result of the rather high bonding energy (945 kJ mol −1 ) between the very strong N�N bond; 35 and facing the competitive hydrogen evolution reaction (HER) from the proton adsorption under a high reduction potential, the unsatisfactory NRR selectivity, 36 causing rather low NH 3 yields and extremely inferior Faradaic efficiency.…”

“…To date, many metal-based catalysts have been designed theoretically or prepared experimentally, including noble-metals (Ru, Rh, Pt, Au, and Ag), transition metal sulfides (CoS 2 and MoS 2 ), nitrides (VN, Mo 2 N), phosphides (δ-AlP 3 ), carbides (Mo 2 C), and oxides (Mo-doped W 18 O 49 and Fe 2 O 3 –CNT). It is generally recognized that the coexistent occupied and empty d orbitals can back-donate π-electrons to and accept lone-pair electrons from N 2 , which determines the origin of the NRR activity for these transition metal (TM) containing catalysts . Despite this, issues still exist.…”