Metal (oxy)hydroxides (MO H, M = Fe, Co, Ni, and mixtures thereof) are important materials in electrochemistry. In particular, MO H are the fastest known catalysts for the oxygen evolution reaction (OER) in alkaline media. While key descriptors such as overpotentials and activity have been thoroughly characterized, the nanostructure and its dynamics under electrochemical conditions are not yet fully understood. Here, we report on the structural evolution of NiCoO H nanosheets with varying ratios of Ni to Co, in operando using atomic force microscopy during electrochemical cycling. We found that the addition of Co to NiO H nanosheets results in a higher porosity of the as-synthesized nanosheets, apparently reducing mechanical stress associated with redox cycling and hence enhancing stability under electrochemical conditions. As opposed to nanosheets composed of pure NiO H, which dramatically reorganize under electrochemical conditions to form nanoparticle assemblies, restructuring is not found for NiCoO H with a high Co content. NiFeO H nanosheets show high roughness as-synthesized which increases during electrochemical cycling while the integrity of the nanosheet shape is maintained. These findings enhance the fundamental understanding of MO H materials and provide insight into how nanostructure and composition affect structural dynamics at the nanoscale.

Mechanistic studies reveal the rate law, an H/D KIE, and that the silane’s electronics impact the thermodynamic and kinetic energetics of the oxidative addition reaction. These electronic effects are relevant in the hydrosilylation of alkynes.

Silanes play a versatile role in catalytic transformations, acting as hydride sources, transmetalation reagents, and starting materials in the synthesis of highly valued organosilicon compounds and polymers. Their use in catalysis with palladium is widespread, commonly proposed to proceed via oxidative addition of Si−H to Pd(0); however, little is known about this fundamental reaction. Here, we show that the formation of silyl palladium hydride complexes (dcpe)PdH(SiR 3 ), which exist in equilibrium with starting materials [(μ-dcpe)Pd] 2 (dcpe = dicyclohexyl(phosphino)ethane) and tertiary silanes HSiR 3 in solution, is dependent on the steric profile of the silanes employed. A lower K eq is observed with increasing steric encumbrance at silicon, correlating well with each substituent's Charton value, and van't Hoff analyses show the reaction with sterically congested silanes to be less thermodynamically favorable. Variable temperature kinetics studies likewise reveal a preference for unhindered silanes as determined by Charton and Eyring analyses. On the other hand, the intramolecular ligand exchange of H/SiR 3 on the formed complexes is unaffected by silane steric bulk. Together, the energetic parameters derived for each of these steps reveal that thermodynamic factors are primarily responsible for favoring (silyl)Pd(H) formation with less sterically bulky silanes. These results present the first systematic study on the role of silane steric effects in oxidative addition of Si−H to Pd(0) and help to inform organosilicon chemistry with late transition metals.

Sixteen insecticide treatments were evaluated on 4 row (40 inch centers) by 49 ft long plots arranged in a randomized complete block design with 4 replications at the Delta Branch Experiment Station, Stoneville, MS. Plots were planted 6 May in a 4 row skip pattern with mustard planted (23 Apr) in the center two rows of the 4 row skip to encourage plant bug establishment. Plots were delimited by alleys formed by cultivating across the rows between plots with a 4 row cultivator. The mustard was cut on 12 Jun and the plant bug population was allowed to establish on the cotton. Insecticides were applied 16 and 20 Jun with a high clearance tractor equipped with 3 TX-3 nozzles per row with 15 inch drops between rows. Evaluations were made by shaking the plants on 3 row ft of two rows onto a 40 inch square cloth and counting plantbugs and beneficial insects.

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