Origin of Nitric Oxide Reduction Activity in Flavo–Diiron NO Reductase: Key Roles of the Second Coordination Sphere

2019 ◽  
Vol 131 (12) ◽  
pp. 3835-3839 ◽  
Author(s):  
Jiarui Lu ◽  
Bo Bi ◽  
Wenzhen Lai ◽  
Hui Chen
Keyword(s):  
Nitric Oxide ◽  
Coordination Sphere ◽  
Oxide Reduction ◽  
Reduction Activity ◽  
Nitric Oxide Reduction ◽  
Second Coordination Sphere

scholarly journals Draft Genome Sequence of an Endophytic Fungus, Gaeumannomyces sp. Strain JS-464, Isolated from a Reed Plant, Phragmites communis

2017 ◽  
Vol 5 (31) ◽  
Author(s):  
Jung A. Kim ◽  
Jongbum Jeon ◽  
Ki-Tae Kim ◽  
Gobong Choi ◽  
Sook-Young Park ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Secondary Metabolites ◽  
Genome Assembly ◽  
Endophytic Fungus ◽  
Draft Genome ◽  
Oxide Reduction ◽  
Phragmites Communis ◽  
Draft Genome Assembly ◽  
Reduction Activity ◽  
Nitric Oxide Reduction

ABSTRACT An endophytic fungus, Gaeumannomyces sp. strain JS-464, is capable of producing a number of secondary metabolites which showed significant nitric oxide reduction activity. The draft genome assembly has a size of 53,151,282 bp, with a G+C content of 53.11% consisting of 80 scaffolds with an N 50 of 7.46 Mbp.

Ultra-Low Amounts of Palladium (0.005-0.05 Wt% Pd) Supported on Titania: Remarkable Low-Temperature Activity for NO Reduction with CO and Structure-Function Property Relationships in Methane Oxidation

2020 ◽  
Author(s):  
Konstantin Khivantsev ◽  
Libor Kovarik ◽  
Nicholas R. Jaegers ◽  
János Szanyi ◽  
Yong Wang
Keyword(s):  
Nitric Oxide ◽  
Carbon Monoxide ◽  
Methane Oxidation ◽  
Steam Reforming ◽  
Methane Steam Reforming ◽  
Oxide Reduction ◽  
Water Steam ◽  
Methane Steam ◽  
Anatase Titania ◽  
Nitric Oxide Reduction

<p>Atomically dispersed Pd +2 cations with ultra-dilute loading of palladium (0.005-0.05 wt%) were anchored on anatase titania and characterized with FTIR, microscopy and catalytic tests. CO infrared adsorption produces a sharp, narrow mono-carbonyl Pd(II)-CO band at ~2,130 cm<sup>-1</sup> indicating formation of highly uniform and stable Pd+2 ions on anatase titania. The 0.05 wt% Pd/TiO<sub>2</sub> sample was evaluated for methane combustion under dry and wet (industrially relevant) conditions in the presence and absence of carbon monoxide. Notably, we find the isolated palladium atoms respond dynamically upon oxygen concentration modulation (switching-on and switching off). When oxygen is removed from the wet methane stream, palladium ions are reduced to metallic state by methane and catalyze methane steam reforming instead of complete methane oxidation. Re-admission of oxygen restores Pd<sup>+2</sup> cations and switches off methane steam reforming activity. Moreover, 0.05 wt% Pd/TiO<sub>2</sub> is a competent CO oxidation catalyst in the presence of water steam with 90% CO conversion and TOF ~ 4,000 hr<sup>-1</sup> at 260 ⁰C. </p><p>More importantly, we find that diluting 0.05 wt% Pd/titania sample with titania to ultra-low 0.005 wt% palladium loading produces a remarkably active material for nitric oxide reduction with carbon monoxide under industrially relevant conditions with >90% conversion of nitric oxide at 180 ⁰C (~460 ppm NO and 150 L/g*hr flow rate in the presence of >2% water steam) and TOF ~6,000 hr<sup>-1</sup>. Pd thus outperforms state-of-the-art rhodium containing catalysts with (15-20 times higher rhodium loading; rhodium is ~ 3 times more expensive than palladium). Furthermore, palladium catalysts are more selective towards nitrogen and produce significantly less ammonia relative to the more traditional rhodium catalysts due to lower Pd amount nd lower water-gas-shift activity. Our study is the first example of utilizing ultra-low (0.05 wt% and less) noble metal (Pd) amounts to produce heterogeneous catalysts with extraordinary activity for nitric oxide reduction. This opens up a pathway to study other Pd, Pt and Rh containing materials with ultra-low loadings of expensive noble metals dispersed on titania or titania-coated oxides for industrially relevant nitric oxide abatement.</p>

A general strategy for designing metal-free catalysts for highly-efficient nitric oxide reduction to ammonia

Fuel ◽  
2021 ◽  
pp. 122442
Author(s):  
Qiang Zhou ◽  
Feng Gong ◽  
Yunlong Xie ◽  
Dawei Xia ◽  
Zhigang Hu ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
General Strategy ◽  
Oxide Reduction ◽  
Metal Free ◽  
Highly Efficient ◽  
Nitric Oxide Reduction
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