Precipitation of Pt, Pd, Rh, and Ru Nanoparticles with Non-Precious Metals from Model and Real Multicomponent Solutions

Abstract

This article presents studies on the precipitation of Pt, Pd, Rh, and Ru nanoparticles (NPs) from model and real multicomponent solutions using sodium borohydride, ascorbic acid, sodium formate, and formic acid as reducing agents and polyvinylpyrrolidone as a stabilizing agent. As was expected, apart from PGMs, non-precious metals were coprecipitated. The influence of the addition of non-precious metal ions into the feed solution on the precipitation yield and catalytic properties of the obtained precipitates was studied. A strong reducing agent, NaBH4 precipitates Pt, Pd, Rh, Fe and Cu NPs in most cases with an efficiency greater than 80% from three- and four-component model solutions. The morphology of the PGMs nanoparticles was analyzed via SEM-EDS and TEM. The size of a single nanoparticle of each precipitated metal was not larger than 5 nm. The catalytic properties of the obtained nanomaterials were confirmed via the reaction of the reduction of 4-nitrophenol (NPh) to 4-aminophenol (NAf). Nanocatalysts containing Pt/Pd/Fe NPs obtained from a real solution (produced as a result of the leaching of spent automotive catalysts) showed high catalytic activity (86% NPh conversion after 30 min of reaction at pH 11 with 3 mg of the nanocatalyst).

Studies on the Application of PGM Nanocatalysts from Spent Automotive Converters for Degradation of Ibuprofen in Aqueous Solutions

“…As shown in our previous studies [ 19 , 20 ], the use of a TiO 2 support facilitated the straightforward separation of the obtained Pt–NPs from the reaction mixture. The synthesized materials underwent preliminary testing in a model catalytic reduction reaction of 4-NPh to 4-APh.…”

Recovery and Isolation Strategies of Platinum, Palladium, and Rhodium from Spent Automotive Catalyst Leachate Using a Polyethylene-Imine-Grafted Cellulose Nanofibril Aerogel

“…Various methods have been investigated for the selective recovery of PGMs, including selective precipitation, solvent extraction, , and ion-exchange processes . Among these methods, ion-exchange has been actively investigated because of its advantageous properties, which include simple operation, eco-friendliness, and good metal-ion enrichment performance. , Pt, Pd, and Rh form negatively charged anionic species in concentrated HCl solution (i.e., the leaching solution for spent catalysts); however, other metal ions generally exist in cationic form, enabling Pt and Pd to be easily separated from other metals using anion-exchange resins .…”

Exploring Enhanced Hydrolytic Dehydrogenation of Ammonia Borane with Porous Graphene-Supported Platinum Catalysts

“…Efficient catalysts for the hydrolysis of AB involve transition metals, such as Pt, Rh, Pd and Ru, among which the precious metal Pt catalyst demonstrates the optimal catalytic activity [16,17]. However, the low abundance and high cost of Pt hinder its widespread application [18][19][20].…”