Influence of organic matter formed during oxidative processes in the catalytic reduction of nitrate

Santos, Ana Sofia Guedes Gorito dos; Restivo, João; Orge, Carla A.; Pereira, M.F.R.; Soares, O.S.G.P.

doi:10.1016/j.jece.2021.105545

Cited by 12 publications

(3 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Conversely, although lower cost Cu suppresses HER, it preferentially produces nitrite and hydroxylamine, which are more toxic than the original nitrate. Tin and bismuth selectively reduce nitrate to N 2 but only at very high potential, and they are highly sensitive to pH, potential, and plane of the exposed crystal facet. , Bimetallic alloys have gained attention for nitrate reduction because they provide dual active sites that enable high activity and selectivity toward nitrate reduction, e.g., Pt–Ir, Pt–Sn, Pt–Ru, Pd–Cu, Au–Ag, and Cu–Ni. − However, most still require significant quantities of high cost platinum group metals.…”

Section: Introductionmentioning

confidence: 99%

Behavior of Cupric Single Atom Alloy Catalysts for Electrochemical Nitrate Reduction: An Ab Initio Study

Gupta,

Rivera,

Shaffer

et al. 2023

ACS EST Eng.

View full text Add to dashboard Cite

Electrochemical nitrate reduction (E-NRR) powered by renewable electricity is a sustainable method of converting toxic nitrate into benign products (N 2 ) or value-added products (NH 3 ). Recently, single atom substitutions of Pd and Ru in inexpensive Cu have shown high activity and selectivity of E-NRR over hydrogen evolution and toward the desired product. Here, we investigate the E-NRR pathway of nine single atom substitutions in Cu to understand the relationship between single atom identity and the activity and selectivity of E-NRR using Density Functional Theory (DFT). We find that while reaction and adsorption energy trends are strongly correlated to the d-band center of the single atom substitution, the single atom catalyst surfaces do not neatly follow scaling relationships as transition states do not occur in the same configuration on all the substitutions. Of the metals investigated, we predict that Ti-, Ru-, Ni-, and Pd-single atom alloys (SAAs) improve the selectivity and activity of E-NRR, while Mo-SAA favors HER, and W-, Pt-, Au-, and In-SAAs do not alter the Cu activity. Ti-, Ru-, and Ni-SAAs selectively reduce nitrate into NH 3 , whereas Pd-SAA reduces nitrate to N 2 at high pH. The selectivity of the SAA for NH 3 or N 2 arises from the preference of adsorbed N* for either the SAA element or Cu. Ni-and Pd-SAA performances are predicted to be more sensitive to potential conditions than Ti and Ru. Overall, this work provides a framework for the design of SAA E-NRR catalysts that are selective to the desired N product.

show abstract

Section: Introductionmentioning

confidence: 99%

Behavior of Cupric Single Atom Alloy Catalysts for Electrochemical Nitrate Reduction: An Ab Initio Study

Gupta,

Rivera,

Shaffer

et al. 2023

ACS EST Eng.

View full text Add to dashboard Cite

show abstract

“…Santos et al [52] verified that the catalytic reduction of NO 3 − in the presence of 1% Pd-1% Cu/CNT catalyst was negatively affected by the presence of a high concentrations of organic matter in solution, being the main reason that led to catalyst deactivation. However, for the experiments conducted in the presence of lower concentrations of organic matter (TOC values around 2 mg L −1 ), efficient catalytic results were obtained.…”

Section: Application To Real Drinking Watermentioning

confidence: 99%

Engineering of Nanostructured Carbon Catalyst Supports for the Continuous Reduction of Bromate in Drinking Water

Costa

Barbosa

Restivo

et al. 2022

Self Cite

View full text Add to dashboard Cite

Recent works in the development of nanostructured catalysts for bromate reduction in drinking water under hydrogen have highlighted the importance of the properties of the metallic phase support in their overall performance. Since most works in catalyst development are carried out in powder form, there is an overlooked gap in the correlation between catalyst support properties and performance in typical continuous applications such as fixed bed reactors. In this work, it is shown that the mechanical modification of commercially available carbon nanotubes, one of the most promising supports, can significantly enhance the activity of the catalytic system when tested in a stirred tank reactor, but upon transition to a fixed bed reactor, the formation of preferential pathways for the liquid flow and high pressure drops were observed. This effect could be minimized by the addition of an inert filler to increase the bed porosity; however, the improvement in catalytic performance when compared with the as-received support material was not retained. The operation of the continuous catalytic system was then optimized using a 1 wt.% Pd catalyst supported on the as-received carbon nanotubes. Effluent and hydrogen flow rates as well as catalyst loadings were systematically optimized to find an efficient set of parameters for the operation of the system, regarding its catalytic performance, capacity to treat large effluent flows, and minimization of catalyst and hydrogen requirements. Experiments carried out in the presence of distilled water as a reaction medium demonstrate that bromate can be efficiently removed from the liquid phase, whereas when using a real water matrix, a tendency for the deactivation of the catalyst over time was more apparent throughout 200 flow passages over the catalytic bed, which was mostly attributed to the competitive adsorption of inorganic matter on the catalyst active centers, or the formation of mineral deposits blocking access to the catalyst.

show abstract

“…The World Health Organization (WHO) recommends not exceeding 10 mg L −1 N-NO 3 − [5]. Currently, one of the major concerns about NO 3 − pollution is the lack of an efficient treatment for its disposal [6]. Most of the current denitrification technologies, such as ion exchange and reverse osmosis, generate a highly concentrated residual NO 3 − brine, which requires further treatment [7][8][9][10], increasing economic and environmental costs.…”

Section: Nitrate (Nomentioning

confidence: 99%

Activity and Stability of Pd Bimetallic Catalysts for Catalytic Nitrate Reduction

et al. 2022

View full text Add to dashboard Cite

In this work, we study the effect of modifying the metal loading (0.5–1.5 wt.% Pd and 0.1–1 wt.% Sn or In), the impregnation order of noble or promoter metal (Pd–Sn or Sn–Pd), and the type of promoter metal (Sn or In) during the preparation process for a Pd bimetallic catalyst, supported on γ-alumina, used in the catalytic reduction of nitrate. The deposition of the noble metal over the promoter metal, especially with Pd:Sn ratios (wt.) of 1:10 and 1:2, favored the hydrogen spillover rate and increased the H concentration on the catalyst surface, enhancing NH4+ production. On the other hand, Pd–In catalysts showed higher activity than the Sn catalysts, as well as higher NH4+ selectivity. The stability of the Pd–Sn/Al2O3 (1.5–1 wt.%) catalyst was evaluated in long-term experiments for the treatment of synthetic water (100 mg L−1 NO3−) and three different commercial drinking waters. This Pd–Sn/Al2O3 catalyst achieved a stable nitrate conversion for a duration of 50 h in the synthetic water treatment. However, the catalyst showed a significant activity loss in the presence of other ions (different to NO3−) in the reaction medium, increasing slightly the selectivity to NH4+.

show abstract

Influence of organic matter formed during oxidative processes in the catalytic reduction of nitrate

Cited by 12 publications

References 36 publications

Behavior of Cupric Single Atom Alloy Catalysts for Electrochemical Nitrate Reduction: An Ab Initio Study

Behavior of Cupric Single Atom Alloy Catalysts for Electrochemical Nitrate Reduction: An Ab Initio Study

Engineering of Nanostructured Carbon Catalyst Supports for the Continuous Reduction of Bromate in Drinking Water

Activity and Stability of Pd Bimetallic Catalysts for Catalytic Nitrate Reduction

Contact Info

Product

Resources

About