Interfacial Phenomenon and Nanostructural Enhancements in Palladium Loaded Lanthanum Hydroxide Nanorods for Heterogeneous Catalytic Applications

Abstract

Hydrogenation and cross-coupling reactions are of great importance for industrial applications and noble metal based catalysts are filling the void since the last few decades. However, the high cost of noble metals and poor recycling performance provides an opportunity for chemists to look for alternate options. Herein, we present the use of Lanthanum hydroxide as support for loading ultra-low amount of Pd for hydrogenation and cross-coupling reactions. Lanthanum hydroxide having controlled morphologies comprises exposed crystallographic facets which interact with small sized Pd NPs and shows versatile and effective catalytic performance. The reduction of 4-NP over Pd/La(OH)3 was achieved within very short time (45s) with a rate constant of 60 × 10−3 s−1. The hydrogenation of styrene was also accomplished within 1 hour with much high TOF value (3260 h−1). Moreover, the Suzuki cross-couplings of iodobenzene and phenyl boronic acid into biphenyl completed within 35 min with a TOF value of 389 h−1. The strong interfacial electronic communication regulates electron density of catalytic sites and lowers energy for adsorption of reactant and subsequently conversion into products. Moreover, abundant hydroxyl groups on the surface of La(OH)3, large surface area, mono-dispersity and ultra-small size of Pd NPs also favors the efficient conversion of reactants.

Effects of cerium and tungsten substitution on antiviral and antibacterial properties of lanthanum molybdate

“…However, the composition difference XPS and ICP was not significant. The valences of La, Mo, and W were identified as La(III), Mo(VI), and W(VI) [ [25] , [26] , [27] ]. For Ce, although S/N ratio of the spectrum was small, it was identified as Ce(III):Ce(IV) = 56:44 by the deconvolution of Ce3d peaks [ 28 , 29 ].…”

One-Pot Synthesized Pd@N-Doped Graphene: An Efficient Catalyst for Suzuki–Miyaura Couplings

“…The corresponding O 1s spectrum could be deconvoluted into four peaks with binding energies of 529.6 eV, 531 eV, 533 eV, and 534.6 eV. The signal at 531 eV could be assigned to oxygen-bonded Pd (Pd-O), while 529.6 eV, 533 eV, and 534.6 eV could be attributed to the presence of -C=O, -C-OH, chemisorbed oxygen (carboxylic groups), and/or water, respectively [37,38]. The high-resolution XPS spectrum of the Pd 3d region (Figure 8) yielded peaks at binding energies of 335.1 eV, 335.8 eV, and 337.6 eV, which corresponded to 3d 5/2 and 340.3 eV, 341.1 eV, and 342.3 eV, which corresponded to 3d 3/2 .…”

Lanthanum‐based catalysts for (bio)ethanol conversion: effect of preparation method on catalytic performance – hard templating versus hydrolysis

“…In fact, one of the advantages of La(OH) 3 is the preferential growth along (100) crystallographic family of planes allowing the synthesis of homogeneous nanorods. 34 Due to the promising activity of La(OH) 3 , in the present paper we report our results for two different preparation routes: hard templating and hydrolysis. It needs to be noted that hard template synthesis was investigated as a novel procedure for the synthesis of lanthanum oxide-based material in the work presented here, and to our knowledge it has not been previously reported in the open literature.…”

“…In heterogeneous catalysis, even though only partially exploited, La(OH) 3 exhibits interesting catalytic properties both as a catalyst in Claisen–Schmidt condensation 37 and as a catalyst support for Pd in the reduction of 4‐nitrophenol into 4‐aminophenol, 34 styrene hydrogenation and Suzuki cross‐coupling reactions. In fact, one of the advantages of La(OH) 3 is the preferential growth along (100) crystallographic family of planes allowing the synthesis of homogeneous nanorods 34 . Due to the promising activity of La(OH) 3 , in the present paper we report our results for two different preparation routes: hard templating and hydrolysis.…”