Noble-metal alloys are widely used as heterogeneous catalysts. However, due to the existence of scaling properties of adsorption energies on transition metal surfaces, the enhancement of catalytic activity is frequently accompanied by side reactions leading to a reduction in selectivity for the target product. Herein, we describe an approach to breaking the scaling relationship for propane dehydrogenation, an industrially important reaction, by assembling single atom alloys (SAAs), to achieve simultaneous enhancement of propylene selectivity and propane conversion. We synthesize γ-alumina-supported platinum/copper SAA catalysts by incipient wetness co-impregnation method with a high copper to platinum ratio. Single platinum atoms dispersed on copper nanoparticles dramatically enhance the desorption of surface-bounded propylene and prohibit its further dehydrogenation, resulting in high propylene selectivity (~90%). Unlike previous reported SAA applications at low temperatures (<400 °C), Pt/Cu SAA shows excellent stability of more than 120 h of operation under atmospheric pressure at 520 °C.

The role of surface hydroxyls is significant for understanding catalytic performance of metallic oxides for CO2 electroreduction reaction (CO2ER). This Communication describes, employing SnO x as a model system, how to moderate coverage of hydroxyl to derive a stable Sn branches catalyst for CO2ER with a 93.1% Faradaic efficiency (FE) of carbonaceous products. With use of in situ attenuated total reflection surface enhanced infrared adsorption spectroscopy (ATR-SEIRAS) and density functional theory (DFT) calculations, we found that a proper amount of surface hydroxyls offered effective sites to boost CO2 adsorption via hydrogen bond. However, a higher surface coverage of hydroxyls leads to self-reduction of Sn–OH. We also explained the competition between self-reduction and CO2 reduction over Sn-based catalysts. The findings revealed the quantitative correlation between surface coverage of hydroxyl and CO2ER activity and suggested a logical extension to other metal oxide catalysts for CO2ER.

Electrocatalytic reduction of carbon dioxide (CO 2 ER) to reusable carbon resources is a significant step to balance the carbon cycle. This Communication describes a seed-mediated growth method to synthesize ultrathin Pd−Au alloy nanoshells with controllable alloying degree on Pd nanocubes. Specifically, Pd@ Pd 3 Au 7 nanocrystals (NCs) show superior CO 2 ER performance, with a 94% CO faraday efficiency (FE) at −0.5 V vs reversible hydrogen electrode and approaching 100% CO FE from −0.6 to −0.9 V. The enhancement primarily originates from ensemble and ligand effects, i.e., appropriately proportional Pd−Au sites and electronic back-donation from Au to Pd. In situ attenuated total reflection infrared spectra and density functional theory calculations clarify the reaction mechanism. This work may offer a general strategy for the synthesis of bimetallic NCs to explore the structure−activity relationship in catalytic reactions.