Enhanced selectivity of 3-D ordered macroporous Pt/Al2O3 catalysts in nitrites removal from water

Recent Progress and Prospects in Catalytic Water Treatment

“…Pt catalysts supported on 3D ordered macroporous alumina synthesized by macrostructuration routes in the presence of monodispersed polymer spheres presented a superior activity and selectivity to N 2 than those supported on classical mesoporous Al 2 O 3 support due to the open structuration and high degree of interconnectivity of the structure favoring the elimination of the OH − produced outside the pores. 212 The same enhancement of nitrite conversion was observed using Pt supported on 3D-ordered macroporous mesoporous silica prepared using dual templating methods. 198 These studies demonstrate that not only the choice of the active phase and the optimization of its dispersion but also the engineering of the pore architecture of the inert support around the active sites are of major importance for developing efficient catalysts for water treatment.…”

“…Hence, the accumulation of the OH – produced during the reaction in the vicinity of the active sites and the internal diffusion limitation of NO 2 – inside the catalytic grains are then detrimental to nitrite conversion and to the selectivity toward N 2 . Pt catalysts supported on 3D ordered macroporous alumina synthesized by macrostructuration routes in the presence of monodispersed polymer spheres presented a superior activity and selectivity to N 2 than those supported on classical mesoporous Al 2 O 3 support due to the open structuration and high degree of interconnectivity of the structure favoring the elimination of the OH – produced outside the pores . The same enhancement of nitrite conversion was observed using Pt supported on 3D-ordered macroporous mesoporous silica prepared using dual templating methods .…”

Opportunities and challenges in aqueous nitrate and nitrite reduction beyond electrocatalysis

“…In drinking water treatment, N 2 formation is a desirable selectivity, while NH 3 /NH 4 + is more desirable for some emerging applications (e.g., ammonia production from waste treatment). Notably, N 2 or NH 3 /NH 4 + production is mainly at the active sites of some stronger-binding elements (e.g., Pd, Pt, and Rh) [18,20,36,38,[102][103][104][105]. Because of that, the selectivity of N 2 and NH 3 /NH 4 + production depends mainly on the reduction phase of nitrite on a strong-binding monometallic site [24,106].…”

A Review on the Catalytic Hydrogenation of Bromate in Water Phase

“…This complex composition could reduce or hinder the efficiency of the catalysts for the removal of specific water pollutants. Recently, several articles were published studying the use of catalytic hydrogenation for the control of some water pollutants like halogenated organic compounds, nitrosamines, nitrate, nitrite, or bromate [9][10][11][12][13][14][15].…”