Combining theory and experiment in electrocatalysis: Insights into materials design

Abstract

Better living through water-splitting Chemists have known how to use electricity to split water into hydrogen and oxygen for more than 200 years. Nonetheless, because the electrochemical route is inefficient, most of the hydrogen made nowadays comes from natural gas. Seh et al. review recent progress in electrocatalyst development to accelerate water-splitting, the reverse reactions that underlie fuel cells, and related oxygen, nitrogen, and carbon dioxide reductions. A unified theoretical framework highlights the need for catalyst design strategies that selectively stabilize distinct reaction intermediates relative to each other. Science , this issue p. 10.1126/science.aad4998

Nickel Hydr(oxy)oxide Nanoparticles on Metallic MoS2 Nanosheets: A Synergistic Electrocatalyst for Hydrogen Evolution Reaction

“…However, the HER activity of the 2H‐MoS 2 /Ni 2+ δ O δ (OH) 2− δ (1:1) hybrid is worse than the 1T‐MoS 2 /Ni 2+ δ O δ (OH) 2− δ (1:1) hybrid. Two differences between 2H‐MoS 2 and 1T‐MoS 2 can be regarded as the main reasons for this result: (1) 1T‐MoS 2 owns HER active sites at both the edges and basal planes while only the metallic edge sites are active for HER in 2H‐MoS 2 ; (2) 1T‐MoS 2 has much better electrical conductivity than 2H‐MoS 2 7, 45, 48…”

“…To address this challenge, many promising strategies such as photocatalytic or photoelectrochemical or electrocatalytic water splitting have been extensively explored 2, 3, 4, 5, 6. Water electrolysis such as water‐alkali electrolyzers or chlor‐alkali electrolyzers currently adopted in industrial processes is more suitable for centralized hydrogen production because the input energy is electricity which can be easily concentrated and be converted from abundant but dispersive energy sources such as wind energy, tide energy, and solar energy 7, 8, 9. However, unsatisfactory performance of the electrocatalysts for both the cathodic hydrogen evolution reaction (HER) and the anodic oxygen evolution reaction (OER) sets a large barrier for cost‐effective hydrogen production.…”

Electrocatalytic Metal–Organic Frameworks for Energy Applications

“…T herefore, the OERi sk inetically challenging, typically requires large overpotentials, and is considered one of the major roadblocksf or the storageo fr enewable energy in chemical fuels. [5,6,64,94,95] Precious-metal-basedc atalysts, such as RuO 2 and IrO 2 ,a re considered the benchmark for the OER;h owever,t heir high cost ands carcity limit their commercial viability. [94,95] The design of earth-abundant catalysts [a] BHT = benzenehexathiolate,T HT = triphenylene-2,3,6,7,10,11-hexathiolate,T HTA = mixed triphenylene-2,3,6,7,10,11-hexathiolate and triphenylene-2,3,6,7,10,11-hexamine.…”

“…Whereas renewable energy penetration in the electricity sector through the utilization of solar, wind, and hydro powert echnologiesh as been significant,t he transportation and industrial sectors require the development of sustainable pathways movingt owardd ecarbonization and electrification. [3,5] Liquid fuels are expected to remain the dominant source of energy for transportation,a lthough the share of total transportation energyi sp rojected to declinef rom 96 %i n2 012 to 88 %i n 2040. [4] One possible strategy to mitigate the intermittent nature of renewable energy sourcesa nd to decreaset he reliance on traditional fossil fuels in the transportation and industrial sectors is through the conversion and storage of renewable energyi n chemicalb onds.…”

“…[1,5,7] Alternatively, an indirect electrochemical pathway for which electricity generated from renewable energy drives the energy conversion is also viable. [5,7] The stored energy can be converted back into electricity to lessen the impact of intermittent reWith the global energy demande xpected to increase drastically over the next several decades, the development of asustainable energy system to meet this increaseisparamount. Renewable energy sources can be coupled with electrochemical conversion processes to store energy in chemical bonds.…”