An 'exceptionally stable' single-atom catalyst

February 24, 2020

Scientists at Tokyo Institute of Technology (Tokyo Tech) have shown that single platinum atoms trapped in C12A7 crystals act as a stable and effective catalyst for the hydrogenation of nitroarenes, an essential process in the production of many kinds of fine chemicals. Their approach could become a versatile route for developing other single-atom catalysts for wide-ranging industrial applications.

Single-atom catalysts (SACs) are on the way to becoming dream catalysts -- ones that exhibit superb performance based on optimized usage of metal atoms. Many research teams around the world have been working to advance the scalable development of SACs since they were first proposed by Tao Zhang and colleagues in China and the US in 2011.

Now, in a proof-of-concept study that throws the door wide open to developing a new range of SACs, researchers at Tokyo Tech have designed and tested a catalyst composed of single platinum atoms trapped in C12A7, a nanoporous crystal widely used in the production of aluminous cement.

The inner structure of C12A7 crystals is "just the right size" for trapping single metal atoms, the researchers say in their paper published in Nature Communications.

"Our approach is rather like a 'diamond-in-a-ring' strategy, where the surface cavity of C12A7 can be regarded as a ring, and the single platinum atom is fixed on the ring as a diamond," says first author Tian-Nan Ye at Tokyo Tech's Materials Research Center for Element Strategy.

Ye explains that C12A7 has a positively charged framework structure composed of twelve sub-nanometer-sized cages, each with an inner diameter of around 0.4 nanometers -- a suitable size for capturing individual metal atoms. Each cage has a positive charge of +1/3, and the surface cavities have an open 'mouth' that can trap single metal atoms through electronic interaction.

The catalyst has been demonstrated to be highly stable and active toward the selective hydrogenation of nitroarenes, an important process often used in the dye and polymer industries. It has a higher turnover frequency (up to 25772 per hour) than that of platinum-based catalysts unsupported by C12A7. Remarkably, the new catalyst even works at temperatures of up to 600°C.

Based on these promising results, the researchers investigated whether the trapping effect might work using other metals. As they predicted, C12A7 was also capable of capturing single atoms of ruthenium and rhodium, indicating that their strategy would be applicable to various transition metals.

"Our findings open countless doors to developing new kinds of SACs for different catalytic processes," says Ye. Due to its exceptionally high thermal stability, the C12A7 support would be able to withstand harsher conditions involved in other industrially important processes such as ammonia synthesis and CO2 reduction.

Ye points out that the development of SACs cannot be separated from the exploration of new materials. This is a key reason why Professor Hideo Hosono's group at Tokyo Tech is uniquely positioned to be a pioneer in SAC research, he says, building on a series of achievements including the development of novel semiconductors, an iron-based superconductor, and the first room-temperature-stable electride.
-end-


Tokyo Institute of Technology

Related Platinum Articles from Brightsurf:

Single atom-thin platinum makes a great chemical sensor
Researchers at Chalmers University of Technology, Sweden, together with colleagues from other universities, have discovered the possibility to prepare one-atom thin platinum for use as a chemical sensor.

Scientists get atomistic picture of platinum catalyst degradation
Degradation of platinum, used as a key electrode material in the hydrogen economy, severely shortens the lifetime of electrochemical energy conversion devices, such as fuel cells.

Addition of sintilimab to pemetrexed and platinum improved progression-free survival
The interim analysis of ORIENT-11, a phase III double-blind randomized trial has shown a nearly two-fold increase in progression-free survival with addition of sintilimab to chemotherapy in patients with advanced or metastatic non-squamous non-small cell lung cancer without EGFR or ALK genomic aberrations, according to research data presented today at the International Association for the Study of Lung Cancer Virtual Presidential Symposium.

Platinum-based chemo may improve survival for some metastatic pancreatic cancer patients
Patients with metastatic pancreatic cancer who had germline or somatic mutations in DNA repair genes had better clinical outcomes after platinum-based chemotherapy, as compared with patients without these mutations.

Platinum-based agents not superior to standard chemotherapy
BIDMC clinician-researchers provide new evidence about the optimal way to treat patients who carry BRCA mutations who have been diagnosed with breast cancer.

Avoidance of apoptotic death via a hyperploid salvage survival pathway after platinum treatment in high grade serous carcinoma cell line models
The cover for issue 62 of Oncotarget features Figure 7, 'Proposed model of the hyperploid pathway as a salvage survival strategy regulated by the G2-M checkpoint,' by Yeung, et al.

Storing energy in hydrogen 20 times more effective using platinum-nickel catalyst
Catalysts accelerate chemical reactions, but the widely used metal platinum is scarce and expensive.

Tungsten suboxide improves the efficiency of platinum in hydrogen production
Researchers presented a new strategy for enhancing catalytic activity using tungsten suboxide as a single-atom catalyst (SAC).

Scientists improve pancreatic cancer diagnosis with multifunctional platinum nanoreactor
Scientists from Shanghai Jiao Tong University, University of Surrey and the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) have developed a multifunctional platinum (Pt) nanoreactor geared towards POC metabolic analysis that performs visual detection and mass spectrometry (MS) fingerprinting simultaneously.

Platinum-graphene fuel cell catalysts show superior stability over bulk platinum
Films of platinum only two atoms thick supported by graphene could enable fuel cell catalysts with unprecedented catalytic activity and longevity, according to a study published recently by researchers at the Georgia Institute of Technology.

Read More: Platinum News and Platinum 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.