Nanoreactor strategy generates superior supported bimetallic catalysts

July 30, 2020

Supported bimetallic catalysts are an important class of catalysts in heterogeneous catalysis. They can be applied in various fields, such as electrocatalysis, biomass conversion, and hydrogen production.

However, traditional impregnation and immobilization methods for synthesizing supported bimetallic nanoparticles (BNPs) are often uncontrollable, thus creating BNPs with non-uniform particle size, low alloy degree and inhomogeneous distribution on the supports. The result is poor catalytic performance and low metal utilization.

To improve the performance and efficiency of the supported BNPs, Prof. WANG Guanghui and Prof. JIANG Heqing from the Qingdao Institute of Bioenergy and Bioprocess Technology (QIBEBT) of the Chinese Academy of Sciences (CAS), in collaboration with Prof. LIU Jian from the Dalian Institute of Chemical Physics (DICP) of CAS, recently proposed a nanoreactor strategy for scalable synthesis of the supported ultrafine BNPs.

This strategy introduces high-quality seeds (Pd nanoclusters) and Au ions into the nitrogen-doped mesoporous polymer (NMP). The NMP is used as a nanoreactor for the seeded growth of PdAu BNPs in solid state during thermal reduction.

"The synthesized Pd1Au1/4 BNPs are very uniform in diameter with an error of 0.5 nm, and are homogeneously dispersed in the NMP support," said Prof. WANG.

The Pd1Au1/4/NMP sample showed enhanced catalytic performance in formic acid (FA) dehydrogenation compared with the monometallic analogues Pd/NMP and Au/NMP.

"The enhanced activity can be attributed to the electronic interaction between Pd and Au in the Pd1Au1/4 BNPs. In addition, the electronic interaction could be adjusted by changing the composition of PdAu BNPs during synthesis," said Prof. JIANG.

Moreover, the PdAu/NMP product can be molded into a monolith by a pellet press under mild pressure (1.0 bar) without any binders, due to its coral-like structure. The monolith contains abundant macropores which can be of benefit for mass transfer in a liquid reaction.

Notably, the monolith of Pd1Au1/4/NMP still exhibits considerable activity in FA dehydrogenation with a TOF value of 3684 h-1 at 333 K, and can be recycled five times without mass loss and changes in activity.

Many other supported Pd-based BNPs (diameters ranging from 2-3 nm) have also been synthesized using this method, including PdRu, PdCo, PdNi, PdZn, PdAg and PdCu BNPs.

This proposed nanoreactor strategy provides an effective route for synthesizing various supported bimetallic catalysts. These catalysts are promising for applications in green and sustainable catalytic processes.
-end-
This study was published in Materials Today on July 30. It was supported by the National Natural Science Foundation of China, QIBEBT and the DNL Cooperation Fund, CAS.

Chinese Academy of Sciences Headquarters

Related Chemical Physics Articles from Brightsurf:

Hyperbolic metamaterials exhibit 2T physics
According to Igor Smolyaninov of the University of Maryland, ''One of the more unusual applications of metamaterials was a theoretical proposal to construct a physical system that would exhibit two-time physics behavior on small scales.''

Challenges and opportunities for women in physics
Women in the United States hold fewer than 25% of bachelor's degrees, 20% of doctoral degrees and 19% of faculty positions in physics.

Indeterminist physics for an open world
Classical physics is characterized by the equations describing the world.

Leptons help in tracking new physics
Electrons with 'colleagues' -- other leptons - are one of many products of collisions observed in the LHCb experiment at the Large Hadron Collider.

Has physics ever been deterministic?
Researchers from the Austrian Academy of Sciences, the University of Vienna and the University of Geneva, have proposed a new interpretation of classical physics without real numbers.

Twisted physics
A new study in the journal Nature shows that superconductivity in bilayer graphene can be turned on or off with a small voltage change, increasing its usefulness for electronic devices.

Physics vs. asthma
A research team from the MIPT Center for Molecular Mechanisms of Aging and Age-Related Diseases has collaborated with colleagues from the U.S., Canada, France, and Germany to determine the spatial structure of the CysLT1 receptor.

2D topological physics from shaking a 1D wire
Published in Physical Review X, this new study propose a realistic scheme to observe a 'cold-atomic quantum Hall effect.'

Helping physics teachers who don't know physics
A shortage of high school physics teachers has led to teachers with little-to-no training taking over physics classrooms, reports show.

Physics at the edge
In 2005, condensed matter physicists Charles Kane and Eugene Mele considered the fate of graphene at low temperatures.

Read More: Chemical Physics News and Chemical Physics Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.