Unsupported Nanoporous Palladium Catalyst for Highly Selective Hydrogenation of Carbon Dioxide and Sodium Bicarbonate into Formate

Abstract

Developing an efficient and simple heterogeneous catalytic system for CO2 conversion into formic acid (FA) is a vibrant research area because FA is recognized as a liquid organic hydrogen carrier. On the basis of our previous work on unsupported nanoporous palladium‐catalyzed hydrogenation proceeding through a Pd‐hydride intermediate, we report herein four types of PdNPore catalysts for the CO2 hydrogenation. The PdNPore‐1 catalyst exhibited high catalytic activity for CO2 hydrogenation into formate and obtained a yield of 86 % at 80 °C under H2 (1.0 MPa) and CO2 (1.5 MPa) with 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU) as a base in acetonitrile. Moreover, the catalyst was easily recovered and reused without any loss of catalytic activity. Sodium bicarbonate could also be hydrogenated using the PdNPore‐1 catalyst.

Unsupported Nanoporous Palladium Catalyst for N‐Formylation of Amines Using CO2 as a Sustainable C1 Source

“…The results indicated that formic acid could be the key intermediate in the N-formylation in this work. Based on the experimental results and previous reports, [27,[29][30][31][32][33][34][35] a plausible reaction mechanism for the Nformylation of amine with CO 2 catalyzed by PdNPore catalyst is proposed in Scheme 7. Initially, PhSiH 3 and H 2 O are coordinated on the surface of the PdNPore catalyst, whereas amine (R 1 R 2 NH) holds a proton of H 2 O to avoid rapid H 2 evolution.…”

“…Unsupported nanoporous metal materials, such as nanoporous gold and nanoporous palladium (PdNPore), have been successfully employed in green and sustainable organic transformations as novel heterogeneous catalysts. [24][25][26][27] The high chemoselectivity, easy recovery, and high reusability of a nanoporous metal catalyst make it a promising heterogeneous catalyst for organic transformations. However, to the best of our knowledge, nanoporous metal catalyzed CÀ N construction using CO 2 as the carbon source has not yet been reported.…”

Impact of the Local Environment of Amines on the Activity for CO2 Hydrogenation over Bifunctional Basic – Metallic Catalysts

“…Wang et al showed heterolytic cleavage between unsupported Pd and various nitrogen containing bases. [26] Detailed mechanistic investigations on the Pd-NH 2 system used in this work are currently ongoing.…”

Synthesis of palladium‐chelated poly(triazine imide) heterogeneous nanocatalysts for reduction of p‐nitrophenol to p‐aminophenol

“…Although the high‐surface area and high‐surface‐to‐volume of small size Pd NPs provide rapid catalytic reactions in practical applications, unsupported‐Pd NPs have the tendency to easily aggregate in solutions, which reduces their high efficiency 28–31 . Hence, the way to overcome or minimize all these drawbacks is the immobilization of metal NPs on a variety of less expensive solid supports, including zeolite, metal oxides, surfactants, polymers and carbon materials, including graphene, graphene oxide, carbon nanotubes, and mesoporous carbon 2,25,32–41 …”

“…[24][25][26][27] Although the high-surface area and high-surface-tovolume of small size Pd NPs provide rapid catalytic reactions in practical applications, unsupported-Pd NPs have the tendency to easily aggregate in solutions, which reduces their high efficiency. [28][29][30][31] Hence, the way to overcome or minimize all these drawbacks is the immobilization of metal NPs on a variety of less expensive solid supports, including zeolite, metal oxides, surfactants, polymers and carbon materials, including graphene, graphene oxide, carbon nanotubes, and mesoporous carbon. 2,25,[32][33][34][35][36][37][38][39][40][41] Recently, graphitic-carbon nitride (g-C 3 N 4 ) materials have attracted numerous interests, arising from not only their ability to provide a valuable extension of carbon in novel material applications but also their exceptional chemical stability and outstanding properties.…”