Dynamic structural changes of supported Pd, PdSn, and PdIn nanoparticles during continuous flow high pressure direct H₂O₂ synthesis

Abstract

The structure of mono- and bimetallic supported Pd, PdSn, and PdIn NPs was monitored with a combination of techniques during continuous H2O2 synthesis with H2O2 production rates up to 580 mmolH2O2 gcat−1 h−1.

The Direct Synthesis of Hydrogen Peroxide Over Supported Pd-Based Catalysts: An Investigation into the Role of the Support and Secondary Metal Modifiers

“…Additionally, it should be noted that the weak signals in the Pd3d XPS spectra for both the 0.5%Pd-0.5%Au/SiO 2 and 0.5%Pd-0.5%Au/Al 2 O 3 catalysts preclude a reliable determination of Pd speciation, although it is possible to infer that Pd 2+ is the dominant ). In recent years a growing focus has been placed on the use non-precious metal containing Pd-based alloys for the direct synthesis of H 2 O 2 including, but not limited to Pb [48], Sn [26,32], Ni [28], Zn [34], Ga [30], Cu [27], Co [49] and Fe [7,10,50]. With these previous studies in mind and with an aim to reduce financial costs associated with catalyst synthesis, we subsequently investigated the efficacy of alloying Pd with a range of abundant transition metals.…”

“…With the performance of PdAu catalysts towards the direct synthesis and subsequent degradation of H 2 O 2 well reported to be highly dependent on catalyst support [25] and a growing interest in the alloying of Pd with more abundant base metals [26][27][28][29][30][31][32][33][34] we now investigate the wider applicability of the excess chloride co-impregnation methodology to catalyst preparation.…”

The Selective Oxidation of Cyclohexane via In-situ H2O2 Production Over Supported Pd-based Catalysts

“…In recent years focus has shifted towards alloying Pd with a range of non-precious metals, with numerous studies reporting the enhanced catalytic efficacy achieved through the introduction of Sn [35,36], Ag [37], Zn [38], Ni [39,40], In [41,42], Sb [43], and Te [44] into Pd nanoparticles. Typically, the improved selectivity of the bimetallic catalysts has been attributed to a combination of a reduction of contiguous Pd ensembles and a modification of Pd oxidation state.…”

Comparing Catalysts of the Direct Synthesis of Hydrogen Peroxide in Organic Solvent: is the Measure of the Product an Issue?

“…For this paper we have reviewed 79 papers dealing with the DS and published since 2000 to date [8–80] (Figure 1). Out of them three regrettably did not report how the amount of H 2 O 2 was measured [81–83] .…”