Rational engineering of oxygen vacancies in a metal oxide-based catalyst represents an effective strategy to regulate catalytic performances by influencing both their electrochemical active surface areas and the microelectronic structure. However, the precise control and modulation of the concentration and uniformity of oxygen vacancies on the catalyst surface still remains inadequately explored and poorly elucidated. Herein, we develop a facile and effective method to prepare a series of In 2 O 3 nanorods with varying oxygen vacancy concentrations for efficient electrolytic CO 2 reduction to formate. Experimental results and theoretical calculations reveal that the abundant oxygen vacancies in the In 2 O 3 catalyst significantly improve CO 2 activation and promote the production of *HCOO intermediates, achieving a maximum formate Faradaic efficiency of 91.2% at −1.27 V vs a reversible hydrogen electrode (RHE) with high partial current density and, meanwhile, superior stability. The underlying relationship between the oxygen vacancy concentration and CO 2 reduction reaction (CO 2 RR) performance was further established. This work offers a feasible strategy to finely tune the oxygen vacancy concentration in p-block metal oxide-based catalysts for highly efficient electrolytic CO 2 RR.

Electrocatalytic ammonia (NH3) synthesis from nitrate (NO3-) is a promising alternative to the Haber–Bosch route that requires high energy input and carbon emissions. However, sluggish anodic oxygen evolution reaction (OER)...

The variable dielectric properties of multilayer structural ceramic/polyolefin composite film substrate materials with silicon dioxide (SiO 2 ) and titanium dioxide (TiO 2 ) powders as fillers and 1,2-polybutadiene/styrene-butadiene-styrene triblock copolymer/ethylene-propylene-diene terpolymer/(1,2-PB/SBS/ EPDM) as polymer matrix were systematically investigated. Single-layer SiO 2 , TiO 2 and SiO 2 /TiO 2 /polyolefin-based composite films denoted as A, B and H, respectively, were prepared by the flow casting method, and then multilayer structural composite substrates with different stacking methods were prepared by the hot pressing method. Four different layering modes were used: ABAB, AABB, ABBA, and BAAB. It was found that the dielectric constants of all four modes were within the scientific range. Compared to the other four types of laminated substrates, however, the fifth composite substrate with four identical film laminations made from a blend of two fillers (HHHH) exhibited better thermal stability and had a lower dielectric loss (0.00206) at 10 GHz compared to the other four types of laminated substrates. On the other hand, the other four types of laminated substrates have better mechanical properties compared to the hybrid substrates. This work provides a new idea for the preparation of oxide ceramic/ polyolefin-based dielectric composites that meet the requirements of different dielectric and thermomechanical properties.