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Catalytic hydrogenation of carbon dioxide to CO by reverse water gas shift reaction plays a vital role in the recycling of the abundant carbon source. Here, the reaction over a series of zeolite L-supported platinum catalysts was systematically investigated to study the promoting role of potassium. The results of activity tests showed that controlled addition of potassium promoter to Pt/L catalyst was beneficial for the catalytic activity and selectivity. It was observed that cage encapsulation by zeolite pores could stabilize Pt nano-particles even at severe reaction conditions. Furthermore, X-ray absorption near edge structure and X-ray photoelectron spectra results demonstrated that the chemical state of platinum was altered by the additional potassium promoter, providing evidence for the formation of Pt-O(OH)-K interfacial sites. Thereafter, the Pt-O(OH)-K interfaces, acting as main active sites to adsorb CO 2 and produce bridge-bonded formate intermediates, were identified by a set of in-situ diffuse reflectance Fourier transform infrared spectroscopy and microcalorimetry measurements. This finding provides new insights into the use of a variety of zeolite as carriers for highly dispersed noble metal in catalytic CO 2 reduction. [ABSTRACT FROM AUTHOR]

[Display omitted] • The Co 3 O 4 -SnO 2 composite was successfully fabricated by annealing the bimetallic oxalates. • SnO 2 as a cocatalyst was indispensable for the improvement of catalytic activity of Co 3 O 4. • The synergy of SnO 2 and Co 3 O 4 afforded the Co 3 O 4 -SnO 2 composite with higher catalytic activity. • The Co 3 O 4 -SnO 2 composite exhibited excellent stability and reusability in PMS activation. • SO 4 •−, •OH, O 2 •−, and 1O 2 jointly contributed to the fast elimination of CAP. In this study, the Co 3 O 4 -SnO 2 composite derived from bimetallic oxalates was rationally fabricated and utilized as a catalyst for peroxymonosulfate (PMS) activation towards the destruction of chloramphenicol (CAP). The physicochemical properties of the Co 3 O 4 -SnO 2 were systematically characterized to discover the relationship between its structure and catalytic performance. SnO 2 as a cocatalyst with high conductivity and stability immensely improved the activity of Co 3 O 4 in the Co 3 O 4 -SnO 2 composite. Approximately 98% of CAP (10 mg/L) was eliminated by the Co 3 O 4 -SnO 2 (0.1 g/L) activated PMS (1.0 mmol/L) at initial pH 7 within 20 min. The rationally designed Co 3 O 4 -SnO 2 composite exhibited higher catalytic activity than Co 3 O 4 , SnO 2 , and other cobalt-based bimetallic oxides (such as Co-Fe, Co-Mn, and Co-Cu) in the PMS activation for the CAP degradation. The synergistic effect of Co 3 O 4 and SnO 2 endowed the Co 3 O 4 -SnO 2 composite with higher conductivity and more electron transfer, which was proved by the electrochemical tests. The presence of SO 4 •−, •OH, O 2 •−, and 1O 2 during the CAP degradation was testified by both quenching experiments and electron paramagnetic resonance (EPR) spectroscopy. In addition, the catalytic mechanism and degradation pathways were further proposed via the characterization of X-ray photoelectron spectroscopy (XPS) and the identification of transformation products, respectively. This work provides a new insight into the preparation of novel catalysts and their application in wastewater treatment. [ABSTRACT FROM AUTHOR]

Interfacial charge separation is an essential issue to restrict catalytic activity of photocatalysts. In this work, we report a promising and easy-to-handle strategy to modulate the activity of a C 60 -based photocatalyst (C 60 @Pt) for visible-light-driven hydrogen evolution reaction (HER) with the coupling of magnetic substance that had weak ferromagnetism (Fe 3 O 4 microbeads as an instance). It is found that Fe 3 O 4 microbeads played a pivotal role in boosting photocatalytic activity and apparent quantum efficiency of C 60 @Pt for visible-light-driven HER, as the weak local magnetic field it induced around C 60 @Pt contributed to facilitating the separation of photo electrons from electron-donor in reaction system. This work shows a promising strategy to enhance photocatalytic activity of C 60 -based photocatalyst (C 60 @Pt as an instance) for visible-light-driven hydrogen evolution by coupling it with magnetic substance Fe 3 O 4 microbeads that had weak ferromagnetism. It is found that the Fe 3 O 4 microbeads played a pivotal role in enhancing photocatalytic activity of C 60 @Pt as the weak local magnetic field it induced around C 60 @Pt contributed to promoting the separation of photo-excited electrons from electron-donor. This strategy effectively boosted hydrogen evolution rate and AQE of C 60 @Pt. [Display omitted] • Modulate activity of C 60 -based photocatalyst via connecting weak magnetic substance. • Promote separation of photo-excited electrons by inducing weak local magnetic field. • AQE was boosted up to 2.5 times with the coupling of weak magnetic substance. • Hydrogen evolution improved up to 3.7 times when connecting weak magnetic substance. • Remarkably improve HER photocatalytic robustness of C 60 -based photocatalyst. [ABSTRACT FROM AUTHOR]