Electrocatalytic Conversion of Carbon Dioxide to Methane and Methanol on Transition Metal Surfaces

Abstract

Fuels and industrial chemicals that are conventionally derived from fossil resources could potentially be produced in a renewable, sustainable manner by an electrochemical process that operates at room temperature and atmospheric pressure, using only water, CO2, and electricity as inputs. To enable this technology, improved catalysts must be developed. Herein, we report trends in the electrocatalytic conversion of CO2 on a broad group of seven transition metal surfaces: Au, Ag, Zn, Cu, Ni, Pt, and Fe. Contrary to conventional knowledge in the field, all metals studied are capable of producing methane or methanol. We quantify reaction rates for these two products and describe catalyst activity and selectivity in the framework of CO binding energies for the different metals. While selectivity toward methane or methanol is low for most of these metals, the fact that they are all capable of producing these products, even at a low rate, is important new knowledge. This study reveals a richer surface chemistry for transition metals than previously known and provides new insights to guide the development of improved CO2 conversion catalysts.

Face the Edges: Catalytic Active Sites of Nanomaterials

“…The electrochemical reduction would keep on going and CO 2 would be further reduced to hydrocarbons. Tests on Au, Ag, Zn, Cu, Ni, Pt, and Fe films all showed the capability to produce methane or methanol 80. A volcano plot with CO binding strength as abscissa and CO 2 reduction current density as vertical coordinates was made by experimental data ( Figure 5 ), suggesting the CO binding is the vital step for CO 2 conversion.…”

“…Dashed lines are to guide the eye. Reproduced with permission 80. Copyright 2014, American Chemical Society.…”

CO2 Reduction: From the Electrochemical to Photochemical Approach

“…Cu is the only elemental metal capable of producing C 1 –C 3 hydrocarbons at significant rates due to its suitable binding energy toward the CO intermediate. Stronger CO binding (on catalysts such as Fe, Ni, Co, and Pt) encourages HER, whereas weaker CO binding (on catalysts such as Sn, Pb and Hg) favors formate formation 113, 114. By combing metals having strong CO binding property with metals having weak CO binding property, one may arrive at an intermediate CO‐catalyst interaction that promotes the formation of higher‐value reduction products.…”

Recent Advances in the Synthesis, Characterization and Application of Zn+‐containing Heterogeneous Catalysts

“…Various approaches have been proposed to address CO 2 emissions, including CO 2 capture and storage,72 electrocatalytic reduction73, 74 or photocatalytic reduction75, 76 of CO 2 . The latter two processes are particularly attractive as they can yield valuable chemicals or fuels.…”