Cu Catalyst Supported on Nitrogen and Phosphorus Co-Doped Carbon Nanosheets for Homocoupling of Terminal Alkynes Using CO₂ as a Soft Oxidant

Abstract

A bifunctional role of carbon dioxide (CO 2 ) was developed in this research as a medium for catalyst preparation and as a soft oxidant for the subsequent coupling reaction. A highly dispersed and low-content Cu catalyst (Cu/NPC) was obtained by homogeneously loading copper oxide (CuO) on porous nitrogen−phosphorus co-doped carbon (NPC) under supercritical-CO 2 (sc-CO 2 ) conditions. Cu/NPC shows an irregular and highly crosslinked three-dimensional (3D) morphology which is assembled by ultrathin and lamellar-like nitrogen−phosphorus co-doped carbon nanosheets. The resulting Cu/NPC catalyst can efficiently promote dehydrogenative homocoupling of terminal alkynes by using CO 2 as a soft oxidant for 1,3-diyne syntheses. Quantitative 1,3-diyne yields up to 99% were achieved with a broad terminal alkyne scope by using Cu/NPC. Additionally, Cu/NPC can be readily reused in the coupling reaction. This research thus demonstrates dehydrogenative homocoupling of terminal alkynes with CO 2 as a renewable, green, readily available, and soft oxidant by using a Cu-based catalyst.

Facile sol–gel fabrication of Cu/N–P-doped C nanocatalysts for peroxymonosulfate activation towards advanced oxidation of 4-nitrophenol

“…3e), it can be decomposed into three P species, which were P–C (131.8 eV and 17.55%), P–N (132.7 eV and 46.65%), P–O (134 eV and 35.8%), and the most abundant species was P–N. 31…”

Highly Efficient Conversion of Homocoupling and Heterocoupling of Terminal Alkynes Catalyzed by AuCu24/AC‐200

“…Conjugated 1,3-diynes are widely used in drug synthesis and the preparation of some organic materials, and also exist in natural products. [1][2][3] In recent years, the synthesis of symmetric and asymmetric 1,3-diynes have been widely concerned. [4][5][6][7] Great progress has been made in obtaining highly active 1,3diynes reactions with copper based catalyst systems.…”

“…Conjugated 1,3‐diynes are widely used in drug synthesis and the preparation of some organic materials, and also exist in natural products [1–3] . In recent years, the synthesis of symmetric and asymmetric 1,3‐diynes have been widely concerned [4–7] .…”

Facile self-propagated carbonization synthesis of phosphorus-doped carbon-based catalysts for partial oxidation and hydrogenation

“…8 The introduction of phosphorus into carbon materials is beneficial for improving electron transfer and thus improving their adsorption capacity, 9 catalytic activity, 10 fire resistance, 11 and chemical stability, 12 with P-doped carbon materials now attracting much attention. 13–15…”

“…8 The introduction of phosphorus into carbon materials is beneficial for improving electron transfer and thus improving their adsorption capacity, 9 catalytic activity, 10 fire resistance, 11 and chemical stability, 12 with P-doped carbon materials now attracting much attention. [13][14][15] There are many ways to dope phosphorus into carbon materials, such as by thermal treatment of carbon-containing precursors mixed/bonded with phosphorus-containing compounds, modification of prefabricated carbon materials with phosphorus-containing compounds, and the co-deposition of carbon and phosphorus from the gas phase. 15 Among them, carbonization of a carbon-containing precursor mixed/combined with a phosphorus-containing compound is commonly used, in which phosphoric acid is widely reported to activate different biomass carbon precursors including glucose, 16,17 sucrose, 18,19 cellulose or lignin 20,21 to prepare phosphorus-containing functional groups on the carbon material.…”