13 Dec 00:52
by Sisi He,
Fenglou Ni,
Yujin Ji,
Lie Wang,
Yunzhou Wen,
Haipeng Bai,
Gejun Liu,
Ye Zhang,
Youyong Li,
Bo Zhang,
Huisheng Peng
A bismuth catalyst with p‐orbital delocalization exhibits the highest rate of CO2 reduction reaction ever reported (391 mg h−1 cm2 at a current density of 500 mA cm−2 with formate Faradaic efficiency of 91 %), which is twice the state‐of‐the‐art synthesized catalysts. Simulations reveal that the p‐orbital localization facilitates adsorption of intermediate *OCHO of CO2 and hence the formation of formate.
Abstract
Enhancing the p‐orbital delocalization of a Bi catalyst (termed as POD‐Bi) via layer coupling of the short inter‐layer Bi−Bi bond facilitates the adsorption of intermediate *OCHO of CO2 and thus boosts the CO2 reduction reaction (CO2RR) rate to formate. X‐ray absorption fine spectroscopy shows that the POD‐Bi catalyst has a shortened inter‐layer bond after the catalysts are electrochemically reduced in situ from original BiOCl nanosheets. The catalyst on a glassy carbon electrode exhibits a record current density of 57 mA cm−2 (twice the state‐of‐the‐art catalyst) at −1.16 V vs. RHE with an excellent formate Faradic efficiency (FE) of 95 %. The catalyst has a record half‐cell formate power conversion efficiency of 79 % at a current density of 100 mA cm−2 with 93 % formate FE when applied in a flow‐cell system. The highest rate of the CO2RR production reported (391 mg h−1 cm2) was achieved at a current density of 500 mA cm−2 with formate FE of 91 % at high CO2 pressure.
28 Mar 08:47
by Margherita De Rosa, Pellegrino La Manna, Annunziata Soriente, Carmine Gaeta, Carmen Talotta, Neal Hickey, Silvano Geremia, Placido Neri
Abstract
The simple tetraminocalix[4]arene 1, which contains weak H-bond-donor NH2 groups, is reported to be a highly efficient organocatalyst for the Vinylogous Mukaiyama Aldol Reaction (VMAR) of 2-(trimethylsilyloxy)furan 5 with α-ketoesters 6 a–l under “on-water” conditions owing to the hydrophobic amplification of weak H-bond interactions. The catalytic efficiency of calixarene catalyst 1 was shown to be closely related to its recognition abilities towards the reactants 5 and 6 through a multipoint recognition model. The proposed model provided good explanations for the differences on the reaction rate acceleration and on the stereoselectivity observed with different substrates.
Supramolecular organocatalysis: The hydrophobic amplification of weak H-bonding interactions makes the simple tetraminocalix[4]arene 1 a highly efficient organocatalyst under “on-water” conditions for the Vinylogous Mukaiyama Aldol Reaction (VMAR) of 2-(trimethylsilyloxy)furan 5 with α-ketoesters 6 a–l.
09 Oct 10:05
by Travis L. Thornell, Benjamin A. Helfrecht, Scott A. Mullen, Abhishek Bawiskar and Kendra A. Erk
ACS Macro Letters
DOI: 10.1021/mz500524d
